This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Ophthalmology
[{'content': "A 56 year old man has painful weeping rashes over the upper eyelid and forehead for the last 2 days along with ipsilateral acute punctate keratopathy. About a year back, he had chemotherapy for Non-Hodgkin's lymphoma. There is no other abnormality. Which of the following is the most likely diagnosis? \nSelect and explain. \nA. Impetigo, B. Systemic Lupus Erythematosus, C. Herpes Zoster, D. Pyoderma gangrenosum", 'role': 'user'}, {'content': 'Answer: C \nExplanation: C i.e. Herpes zoster', 'role': 'assistant'}]