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: Physiology
[{'content': 'Mydriasis is due to \nSelect and explain. \nA. Relaxation of ciliary muscle, B. Relaxation of radial muscle, C. Contraction of ciliary muscle, D. Contraction of radial muscles', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]