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
[{'content': 'Most impoant muscle which opens mouth is \nSelect and explain. \nA. Lateral pterygoid, B. Medical pterygoid, C. Masseter, D. Temporalis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The lateral pterygoid may be regarded as the key muscle of this region because its relations provide a fair idea about the layout of structures in the infratemporal fossa. the relations are as follows: Superficial 1.masseter 2.Ramus of the mandible 3.Tendon of the temporalis 4.The maxillary aery Deep 1.mandibular nerve 2.middle meningeal aery 3.Sphenomandibular ligament 4.Deep head of the medial pterygoid <img src=" /> REF.VOL.3,SIXTH EDITION vol3 pg 118', 'role': 'assistant'}]