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: Anatomy
[{'content': 'Oral diaphragm is formed by: \nSelect and explain. \nA. Mylohyoid muscle, B. Genioglossus muscle, C. Buccinator muscle, D. Orbicularis oris muscle', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]