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: Forensic Medicine
Cause of Berry aneurysm: AIIMS 11 
Select and explain. 
A. Degeneration of internal elastic lamina, B. Degeneration of media/muscle cell layer, C. Deposition of mucoid material in media, D. Low grade inflammation of vessel wall
B: Degeneration of media/muscle cell layer
Answer: B: Degeneration of media/muscle cell layer 
Explanation: Ans. Degeneration of media/muscle cell layer