Final answer:
The parser Control command -STOP is used to halt parsing when errors are encountered, ensuring data integrity and preventing further processing of incorrect data.
Step-by-step explanation:
The parser Control command -STOP is used to instruct a parser to cease parsing operations in the event of encountering errors. This command is particularly useful in scenarios where it's critical to maintain data integrity and immediate attention is required upon error detection. Failing to stop could lead to further processing of incorrect data and potentially propagate errors further down the pipeline. Therefore, option A, Stop parsing in case of errors, is the correct answer to what the -STOP command does.