The most common cause of subarachnoid hemorrhage is:
Aeriovenous malformation
Cavernous angioma
Aneurysm
Aneurysm
Answer is C (Aneurysm): The most common cause of subarachnoid haemorrhage is rupture of a saccular aneurysm (Saccular aneurysms are synonymous with Berry Aneurysms or 'Circle of Willi's aneurysms' and most commonly occur in the anterior circulation on the Circle of Willis).