What should candidates do if they wish to change an answer after marking the answer sheet?

In the context of a standardized testing environment, when a candidate wishes to change an answer after marking their answer sheet, the proper procedure is to carefully erase the original mark and then blacken the circle corresponding to the final answer. This method ensures clarity in the scoring process, as answer sheets are typically scanned or read by machines that detect marked answers. If an original mark is left on the sheet, it may create confusion or lead to scoring errors.

Erasing the initial mark ensures that only the candidate's intended response is recorded, minimizing the chance of ambiguity that could arise from overlapping marks. This practice aligns with common rules and guidelines provided by testing authorities to ensure accurate assessments. Therefore, the careful erasure and replacement of marks show attention to detail and compliance with testing protocols, which is essential for maintaining the integrity of the examination process.

In contrast, simply marking a new answer without erasing could lead to confusion, while seeking a new answer sheet would be unnecessarily complicated and not a standard procedure. Submitting a request to change an answer is not typically an available option during most examinations.