An elderly patient had gastric surgery due to a gastrointestinal bleed 3 days ago, and he has been stable since the surgery. This evening, his daughter tells the nurse, "He seems to be more confused this afternoon. He's never been like this. What could be the problem?" The nurse reviews the patient's medication record and suspects that which drug could be the cause of the patient's confusion?

a. cimetidine (Tagamet)
b. pantopraole (Protonix)
c. clarithromycin (Biaxin)
d. sucralfate (Carafate)