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': 'In complete denture construction labio-dental sound F & V are used to determine the: \nSelect and explain. \nA. Vertical placement of upper anterior teeth, B. Labia-lingual position of anterior teeth, C. Anterio posterior position of anterior teeth, D. Space between tongue and anterior part of hard palate', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]