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
The severity of Mitral stenosis is clinically best decided by - 
Select and explain. 
A. Length of diastolic murmur, B. Intensity of diastolic murmur, C. Loudness of first heart sound, D. Split of second heart sound
A: Length of diastolic murmur
Answer: A: Length of diastolic murmur 
Explanation: None