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 common cause of aoic aneurysm is: 
Select and explain. 
A. Syphilis, B. Marfan's syndrome, C. Atherosclerosis, D. Congenital
C: Atherosclerosis
Answer: C: Atherosclerosis 
Explanation: Answer is C (Atherosclerosis) 'The most common pathologic condition associated with aoic aneurysm is Atherosclerosis':