Final answer:
The nurse could be basing care on the conceptual model of Orem, specifically Orem's Self-Care Deficit Theory.
Step-by-step explanation:
The nurse could be basing care on the conceptual model of c. Orem. Orem's Self-Care Deficit Theory emphasizes the importance of assisting individuals in meeting their self-care needs when they are unable to do so independently. In this case, the nurse is providing care for a postoperative patient who is unable to feed himself and complete basic activities of daily living, which aligns with Orem's theory.