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
Amrinone acts by- 
Select and explain. 
A. Inhibiting phosphodiesterase, B. ATPase inhibitor, C. Calcium channel blocker, D. IC/ channel opener
A: Inhibiting phosphodiesterase
Answer: A: Inhibiting phosphodiesterase 
Explanation: Ans. is 'a' i.e., Inhibiting phosphodiesterase o Amrinone inhibits phosphodiesterase III