Final answer:
The sternohyoid muscle is classified as an infrahyoid muscle, the frontalis is part of the occipitofrontalis with two bellies, and the mentalis elevates and protrudes the lower lip. There is no clear match for the hyoglossus without further details.
Step-by-step explanation:
To answer the question, let's match each muscle with the correct description given the options provided:
- a. sternohyoid - 2. classified as an infrahyoid muscle.
- b. hyoglossus - The hyoglossus originates on the hyoid bone and moves the tongue downward and flattens it, but this action is not listed in the descriptions provided. None of the descriptions explicitly describe the hyoglossus, so it can't be matched with certainty based on the information given.
- c. frontalis - This muscle is part of the occipitofrontalis, which has two bellies. Therefore, it is likely to be 3. consists of two bellies.
- d. mentalis - 4. elevates and protrudes lower lip, describing the action of the mentalis muscle.
The provided descriptions discuss the sternohyoid and the mentalis, but there is no clear match for the hyoglossus based on the given descriptions. We assume the frontalis is part of the occipitofrontalis and therefore associate it with two bellies. The sternohyoid fits correctly as an infrahyoid muscle which depresses the hyoid bone. The mentalis muscle effectively causes the lower lip to protrude and elevate, matching description 4 perfectly.