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: Dental
[{'content': "The initial sign of sexual maturity in boys is usually\nA) Fat spurt\nB) Development of Adam's apple\nC) Change in voice\nD) Appearance of facial hair \nSelect and explain. \nA. BC, B. AC, C. ABC, D. BD", 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]