Final answer:
The Air Force Installation & Mission Support Center (AFIMSC) is comprised of six primary subordinate units (PSUs), with option (a) being the correct answer to the student's question.
Step-by-step explanation:
The Air Force Installation & Mission Support Center (AFIMSC) is a key organizational unit within the United States Air Force that acts as a single hub for managing and supporting installations and missions. The foundation of AFIMSC is made up of six primary subordinate units (PSUs). These PSUs are specialized to deliver specific types of support across the Air Force, covering areas such as security forces, civil engineering, base communications, and more. The correct answer to the question of how many primary subordinate units make up the foundation of AFIMSC is six, which corresponds to option (a).