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: Pharmacology
Epinephrine act by stimulating: 
Select and explain. 
A. Adenyl cyclase, B. Phosohodiestaerse, C. Phospholipase, D. None
A: Adenyl cyclase
Answer: A: Adenyl cyclase 
Explanation: None