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 labiodental sounds are \nSelect and explain. \nA. f,v,ph, B. s,z,c, C. f,z,s, D. f,v,z', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]