Final answer:
The lateral pterygoid muscle is involved in opening the jaw and protruding it, which helps in the process of mastication alongside other muscles such as the masseter.
Step-by-step explanation:
The lateral pterygoid muscle is responsible for opening the jaw and protruding it. While the masseter and temporalis muscles are primarily responsible for elevating and closing the jaw during the process of mastication (chewing), the lateral pterygoid assists in chewing and moving food within the mouth by protruding the mandible. Alongside the lateral pterygoid, the medial pterygoid also assists in moving the mandible from side to side.