A 62-year-old man with diabetes and hypertension is admitted to the emergency department because he has a severe headache and acute onset of double vision. Examination reveals that the man has ptosis...

A 62-year-old man with diabetes and hypertension is admitted to the emergency department because he has a severe headache and acute onset of double vision. Examination reveals that the man has ptosis on the right side and an inability to elevate or adduct the right eye, although lateral eye movements are spared. The man’s right pupil is dilated and unreactive. What is the most likely diagnosis? A. Myasthenia gravis B. Pontine hemorrhage C. Extradural hemorrhage D. Diabetic palsy of cranial nerve III E. Berry aneurysm of the right posterior communicating artery