A 63-year-old man with a history of diabetes, HTN, and intermittent AF has sudden onset of vision loss in his left eye. He says it was as though someone pulled down a curtain over his eye. His...

A 63-year-old man with a history of diabetes, HTN, and intermittent AF has sudden onset of vision loss in his left eye. He says it was as though someone pulled down a curtain over his eye. His symptoms resolved after about 20 minutes. Which structure was most likely to have been affected?

A. Optic nerve

B. Retina

C. Optic chiasm

D. Optic tract

E. Visual cortex