This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Head and neck, Subject name: Anatomy
Opening of jaw is done by 
Select and explain. 
A. Temporalis, B. Lateral pterygoid, C. Med pterygoid, D. Masseter
B: Lateral pterygoid
Answer: B: Lateral pterygoid 
Explanation: Lateral pterygoid is sho, conical, and has upper and lower heads. The lateral pterygoid: - depress mandible to open mouth, with suprahyoid muscles. - protrudes mandible - right lateral pterygoid turns the chin to left side.