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: Psychiatry
Most accurate treatment of erectile dysfunction - 
Select and explain. 
A. Sildenafil, B. Master and Johnson technique, C. Beta blockers, D. Papaverine
A: Sildenafil
Answer: A: Sildenafil 
Explanation: Sildenafil is the DOC for erectile dysfunction.