Final answer:
The correct answer is c. courtesy. It is a medical staff membership category for physicians who occasionally admit patients to the hospital.
Step-by-step explanation:
The correct answer is c. courtesy. In medical settings, the category of medical staff membership for physicians who occasionally admit patients to the hospital is known as a courtesy staff membership. This category allows physicians to admit patients on a limited basis and often requires them to work closely with the hospital's medical staff for coordination and patient care.