A 45-year-old female has a sudden and excruciating headache. Looking herself in the mirror, she notices that one of her eyelid is drooping. When she lifts the eyelid with her fingers, she notices that the eyeball is looking down and out and that her pupil is huge. Neurological examination reveals that she has blurred and double vision.

A magnetic resonance angiogram scan shows the presence of an aneurysm of the circle of Willis. Considering the signs and symptoms of the patient, in which artery is the aneurysm most likely localized?