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
Mouth opening is due to action of 
Select and explain. 
A. Lateral pterygoid, B. Medial pterygoid, C. Temporalis, D. Masseter
A: Lateral pterygoid
Answer: A: Lateral pterygoid 
Explanation: None