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: Pharmacology
[{'content': 'Atropine is substituted by phenylephrine to facilitate fundus examination when: \nSelect and explain. \nA. Mydriasis is required without cycloplegia, B. Cycloplegia is required, C. Mydriasis and cycloplegia both are required, D. Cycloplegia and Mydriasis both are not required', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]