## Core Concept
The omohyoid muscle is a neck muscle that plays a role in the movement of the hyoid bone and the larynx. It is supplied by a branch of the cervical plexus. Understanding the innervation of the omohyoid muscle requires knowledge of the cervical plexus and its branches.

## Why the Correct Answer is Right
The omohyoid muscle is innervated by the **ansa cervicalis**, which is a loop of nerve fibers from the cervical plexus. More specifically, the ansa cervicalis provides motor innervation to the infrahyoid muscles, including the omohyoid muscle. This innervation allows for the muscle's functions, including the depression and lateral movement of the hyoid bone.

## Why Each Wrong Option is Incorrect
* **Option A:** Incorrect because it does not accurately represent the nerve supply to the omohyoid muscle. Without the specific option details, we acknowledge that A is not associated with the known innervation.
* **Option B:** Incorrect for similar reasons; it does not correctly identify the nerve supply to the omohyoid muscle.
* **Option D:** Incorrect as it is not the correct nerve supplying the omohyoid muscle.

## Clinical Pearl / High-Yield Fact
A key point to remember is that the **ansa cervicalis** is a component of the cervical plexus that supplies several infrahyoid muscles, including the omohyoid, sternohyoid, sternothyroid, and thyrohyoid muscles. This is crucial for understanding neck anatomy and the functions of muscles in this region.

## Correct Answer: C. Ansa cervicalis.