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
70 year old man has abdominal pain with mass inabdomen. Angiography reveals aneurysm of aoa. Mostlikely cause is: 
Select and explain. 
A. Trauma, B. Atherosclerosis, C. Syphilis, D. Congenital
B: Atherosclerosis
Answer: B: Atherosclerosis 
Explanation: . Atherosclerosis