According to IIA guidance, which of the following activities are typically primary objectives of engagement supervision?

a. Enable training and development of staff, identify engagement objectives, and assign responsibilities to individual auditors

b. Identify engagement objectives, assign responsibilities to individual auditors, and approve the engagement program

c. Assign responsibilities to individual auditors, approve the engagement program, and enable training and development of staff

d. Approve the engagement program, enable training and development of staff, and identify engagement objectives