A 67-year-old man with a history of hypertension, atrial fibrillation, and diabetes mellitus is brought to the emergency department after sudden-onset right-sided weakness and slurred speech. On examination, he has: •Right-sided facial droop and arm weakness (muscle strength: 1/5 in the right arm, 3/5 in the right leg) •Mild right leg weakness •Right-sided sensory loss •Leftward gaze preference A non-contrast CT scan shows an ischemic stroke in the left cerebral hemisphere. Question: Which artery is most likely affected in this patient?
