CompTIA AT0-001 Practice Test 2026

Answer Option (Which option is correct) A. True
Explanation:

Local scope prevents unintended access through a shared global name.

Why the other options are incorrect:

B. False:
False denies the usual local-scope behavior. Function assignments normally use a local namespace. They do not automatically change global variables.

References:

Python: functions and control flow

Python: built-in types

Answer Option (Which option is correct) A. Convert the value before arithmetic
Answer Option (Which option is correct) D. Validate that the value is numeric
Explanation:

The environment supplies "3" as text, so it must be converted to a numeric type before addition or comparison. Option A makes arithmetic operate on a number. Option D checks that the supplied text represents an acceptable numeric value before conversion and use, so invalid input produces a clear error rather than unintended string processing.

Why the other options are incorrect:

B. Concatenate "1" to increase numerically:
Concatenation joins text rather than adding numbers. Appending a digit produces a different string. Numeric conversion must precede arithmetic.

C. Treat all strings as already numeric:
Strings retain their text type until converted. Their numeric-looking contents do not change that type. Treating them as integers can cause errors or wrong results.

References:

Python: functions and control flow

Python: built-in types

Answer Option (Which option is correct) A. Conditional statement
Explanation:

A conditional statement evaluates whether free space is below the threshold before running cleanup. The action belongs inside the branch whose condition is true. This implements the requirement that cleanup must not run when sufficient space remains.

Why the other options are incorrect:

B. Unconditional loop:
An unconditional loop repeats without requiring low space. It lacks the stated threshold decision. Cleanup could run when it is unnecessary.

C. Git tag:
A Git tag identifies a repository revision. It does not evaluate free disk space. Naming code cannot replace the cleanup condition.

D. Package lock:
A package lock records dependency resolution information. It does not control whether this cleanup executes. The script still needs a threshold check.

References:

Python: functions and control flow

Python: built-in types

Supplied source solution: len([4,5]) -> C. 2; int("7") + 1 -> B. 8; 3 > 9 -> A. FALSE
Explanation:

The list contains two elements, so len([4,5]) matches C, 2. Converting "7" to an integer and adding one gives 8, which matches B. The comparison 3 > 9 is false, which matches A. Each expression must be evaluated according to its own operation rather than the visual order of the choices. Import review: The source solution is preserved above. The sample does not establish the application's ColumnMatch answer representation, so the existing answer-storage fields remain unchanged.

Why the other options are incorrect:

Not applicable: the supplied items are sequence steps or matching choices, rather than incorrect distractors.

References:

Python: built-in types

Python: functions and control flow

Answer Option (Which option is correct) B. A destination parameter
Explanation:

A destination parameter lets each caller provide its own backup location while using the same function. The function can validate that input before writing data. Keeping the destination outside the shared implementation avoids a separate hardcoded function for every caller.

Why the other options are incorrect:

A. A commit hash only:
A commit hash identifies a source revision. It does not specify a backup destination by itself. The caller needs an explicit destination input.

C. A syntax error:
A syntax error prevents valid execution. It is not a function input design. Introducing one would break the backup workflow.

D. A hardcoded global destination:
A hardcoded global destination fixes shared configuration outside the call. Different callers cannot supply destinations independently through it. A parameter provides the required flexibility.

References:

Python: functions and control flow

Python: built-in types

Answer Option (Which option is correct) B. Correlation ID
Answer Option (Which option is correct) C. Timestamp
Explanation:

Option B provides a correlation ID that connects log entries belonging to the same request or automation run. Option C supplies a timestamp that helps reconstruct when those events occurred. Together they support cross-component troubleshooting without disclosing authentication material.

Why the other options are incorrect:

A. Private key:
A private key is secret authentication material. Recording it can enable unauthorized access. Traceability requires nonsecret event metadata instead.

D. Plaintext bearer token:
A bearer token grants access to whoever possesses it. Plaintext logging exposes that capability. Request tracing should preserve context without revealing credentials.

References:

OpenTelemetry: log timestamps and trace correlation

GitHub Actions: secure use

Answer Option (Which option is correct) B. ^[0-9]{3}$
Explanation:

B is the supplied source answer, retained with an ambiguity note. The character class [0-9] selects ASCII digits, and {3} requires three occurrences. However, Python's $ anchor can match before a final newline, so a normal match can accept "123\n". Because the question does not identify the regex engine, flags, or matching API, this is not an unconditionally verified whole-string pattern. For an exact Python check, use fullmatch with [0-9]{3} or clarify the question's assumptions.

Why the other options are incorrect:

A. [0-9]+:
[0-9]+ permits one or more digits. It does not enforce a count of three. This differs from the source's intended fixed-length pattern.

C. [0-9]{2}:
[0-9]{2} requires two digits in the matched portion. It also lacks whole-input anchoring. It does not express the supplied three-digit requirement.

D. ^[a-z]{3}$:
[a-z] selects lowercase letters rather than digits. A count of three does not change that character class. This expression targets a different input category.

References:

Python: regular expression syntax

Answer Option (Which option is correct) B. False
Explanation:

An unquoted false is Boolean; a quoted "false" is a string.

Why the other options are incorrect:

A. True:
True would classify the unquoted literal as text. JSON treats the literal as a Boolean value. Quotation marks are needed to express a string.

References:

Python: JSON encoding and decoding

Answer Option (Which option is correct) A. {"port":443}
Explanation:

The document has a quoted property name and a numeric value inside braces. JSON requires object member names to be strings enclosed in double quotation marks. The number 443 is a valid JSON value, so this representation satisfies the required syntax.

Why the other options are incorrect:

B. {"port":443,}:
The trailing comma appears after the last member. Standard JSON does not allow that separator there. Removing it restores valid object syntax.

C. {port:443}:
The unquoted property name violates JSON syntax. Object member names must be strings. The identifier needs double quotation marks.

D. {'port':443}:
The single quotes are not JSON string delimiters. JSON uses double quotes for member names. Python-like dictionary notation is not interchangeable with JSON.

References:

Python: JSON encoding and decoding

Answer Option (Which option is correct) A. Indentation
Explanation:

YAML indentation expresses the relationship between a mapping and its nested content. Aligning a nested line with its parent can move it to the wrong level or make the structure invalid. Restore the intended indentation and validate the resulting document before applying it.

Why the other options are incorrect:

B. DNS TTL:
DNS TTL controls how long answers may be cached. It cannot change YAML nesting. The malformed mapping remains malformed.

C. HTTP method:
An HTTP method defines an API operation. It does not repair a configuration file's indentation. Parsing must succeed before the intended request configuration can be used.

D. Git author name:
The Git author name describes commit authorship. It is unrelated to the mapping's structure. Updating it leaves the nested YAML line unchanged.

References:

YAML 1.2.2 specification