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
Oral diaphragm is formed by: 
Select and explain. 
A. Mylohyoid muscle, B. Genioglossus muscle, C. Buccinator muscle, D. Orbicularis oris muscle
A: Mylohyoid muscle
Answer: A: Mylohyoid muscle 
Explanation: None