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 patient Mohan, aged 60 years, needs an eye examination. He needs a drug which will dilate his eyes but not paralyse his ciliary muscles – \nSelect and explain. \nA. Atropine, B. Phenylephrine, C. Cyclopentolate, D. Tropicamide', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Cycloplegics cause paralysis of accommodation and dilate the pupil → Atropine, homatropine, Cyclopentolate.\nOnly mydriatic (dilate pupil) but no cycloplegia →\xa0\xa0 Phenylephrine.', 'role': 'assistant'}]