A nurse is teaching a student about what type of clients require parenteral nutrition (PN). Which of the following statements will alert the nurse that further teaching is required?

a) Clients with malabsorption syndromes may need PN.
b) Clients with a functioning gastrointestinal tract may need PN.
c) Clients who cannot tolerate enteral nutrition may need PN.
d) Clients with a healthy appetite may need PN.