How should candidates indicate their answers on the examination?

Candidates should indicate their answers on the examination by darkening the appropriate 'lettered' circle on a separate answer sheet. This method is commonly used in standardized testing because it allows for efficient and accurate scoring. The use of a separate answer sheet minimizes the risk of errors that could occur from altering or marking the exam paper directly, and it also aids in the scanning process by automatic grading systems. Darkening a circle ensures that the scantron or optical mark recognition systems can correctly interpret the selected answers without ambiguity, allowing for a quicker grading process and reducing the potential for misinterpretation of handwritten responses. This practice also keeps the exam paper clean and free of markings, which maintains a standard format for all test-takers.