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 common cause of subarachnoid hemorrhage is: 
Select and explain. 
A. Aerio-venous malformation, B. Cavernous angioma, C. Aneurysm, D. Hypeension
C: Aneurysm
Answer: C: Aneurysm 
Explanation: Answer is C (Aneurysm): `The most common cause of subarachnoid haemorrhage is rupture of a saccular aneurysm (excluding head trauma)' - Harrison. Previously asked frequently as follows: (Excluding hand trauma) Most common cause of subarachnoid haemorrhage is rupture of a saccular aneurysmQ Most common cause of subarachnoid haemorrhage is rupture of a Berry aneurysmQ Most common cause of subarachnoid haemorrhage is rupture of 'Circle of Willis' aneurysmQ. (Saccular aneurysms are synonymous with Berry Aneurysms and most commonly occur in the anterior circulation on the Circle of Willis).