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: Pathology
Calcification of the aortic valve is seen in - 
Select and explain. 
A. Aortic stenosis, B. Aortic regurgitation, C. Marfan's syndrome, D. Hurler's syndrome
A: Aortic stenosis
Answer: A: Aortic stenosis 
Explanation: None