An Internal Auditor Used a Questionnaire During an Interview to Gather

An internal auditor used a questionnaire during an interview to gather information about the nature of credit sales processing. The questionnaire did not cover some pertinent information offered by the person being interviewed, and the auditor did not document the potential problems for further investigation. The primary deficiency with the above process is that:

A) The auditor failed to consider the importance of the information offered.
B) A questionnaire was used in a situation where a structured interview should have been used.
C) The use of a questionnaire precluded the auditor from documenting other information.
D) The engagement program was incomplete.