Question

the muscle that moves the lower jaw up to close the mouth when chewing is the _______. frontalismassetersternocleidomastoidtemporalis

Explanation:

The masseter is the primary muscle for closing the mouth during chewing, elevating the mandible (lower - jaw). The frontalis is on the forehead, the sternocleidomastoid is involved in head movement, and the temporalis also helps in jaw movement but the masseter is the main one for this action.

Answer:

B. masseter