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: Medicine
Most commonly affected value in subacute bacterial endocarditis is: 
Select and explain. 
A. Mitral, B. Tricuspid, C. Pulmonary, D. None of the above
A: Mitral
Answer: A: Mitral 
Explanation: None