This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
In a patient with a transplanted hea which of these are the reasons for increased cardiac output during exercise: 
Select and explain. 
A. Reinnervation of transplanted hea by vagus, B. Intrinsic mechanism, C. Epinephrine from medulla, D. Bainbridge reflex
C: Epinephrine from medulla
Answer: C: Epinephrine from medulla 
Explanation: C i.e. Epinephrine from medulla