Final answer:
The correct answer is option 1. The chief audit executive is responsible for providing appropriate supervision, reviewing work programs, and ensuring objective communications.
Step-by-step explanation:
When engagements are performed for the internal audit activity by non-staff members, the chief audit executive is responsible for providing appropriate supervision from the beginning to the conclusion of the engagement.
The chief audit executive is also responsible for reviewing the engagement work programs for approval and ensuring that the engagement communications are objective, clear, and timely.
Therefore, the correct option in this case is 1) providing appropriate supervision from the beginning to the conclusion of the engagement.