A maintenance-window script must accept a list of library branch codes from a config file. Which YAML form correctly represents that list as script input?
Select an answer to reveal the explanation.
Short Explanation
Use the YAML sequence of branch code strings so your script can loop through each branch cleanly. Prose paragraphs and Base64 blobs won't give you dependable list input, and duplicate-key mappings aren't real YAML lists.
Full Explanation
The correct form is the YAML sequence (list) of branch code strings that the script iterates. YAML sequence markers, or inline flow lists, express multiple branch codes as discrete values, so the script can iterate each code and apply maintenance logic per branch. The single unquoted paragraph of prose with no list markers is free text, not structured list input the script can reliably iterate as discrete branch codes. The binary blob encoded as Base64 with no YAML structure hides branch codes behind opaque encoding and defeats readable municipal configuration. The mapping that uses identical keys repeated to fake list input is invalid or last-key-wins in YAML and is not dependable list encoding. Exam caveat: quote branch codes that look like numbers or booleans if needed, validate codes against allow-list of real library branches, and keep sequence under clear key such as branch_codes for readability. Operational check: load YAML fixture with three branch codes, assert script iterates all three, reject configs that supply prose or duplicate-key hacks, and run maintenance-window dry-run that names each branch before changing anything in production libraries.