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
Most important muscle which opens mouth is - 
Select and explain. 
A. Lateral pterygoid, B. Medical pterygoid, C. Masseter, D. Temporalis
A: Lateral pterygoid
Answer: A: Lateral pterygoid 
Explanation: Lateral pterygoid depresses the mandible to open the mouth, with suprahyoid muscles.