This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: A.N.S., Subject name: Pharmacology
[{'content': 'shortest acting mydriatic \nSelect and explain. \nA. Atropine, B. Tropicamide, C. Homatropine, D. Cyclopentolate', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. (b) Tropicamide', 'role': 'assistant'}]