What Is the Best Way to Describe What Happens During

What is the best way to describe what happens during a Cerebral Aneurysm?

A) An obstruction or narrowing of the lumen of the aorta and its major branches.
B) An obstruction of an artery at the brain stem which results in lack of oxygen to the brain.
C) Blood flow exerts pressure against a weak artery wall resulting in a rupture of the arterial wall.
D) Inflammation of the brain and spinal cord meninges that affects all three meningeal membranes.