Okay, let's tackle this question about the occipital bellies of the occipitofrontalis muscle. The question is asking which nerve supplies this part of the muscle. First, I need to recall the anatomy of the facial muscles and their innervation.

The occipitofrontalis muscle has two parts: the frontal belly and the occipital belly. They are connected by the epicranial aponeurosis. The frontal belly is responsible for raising the eyebrows and is innervated by the facial nerve, specifically the temporal branch. The occipital belly, on the other hand, is involved in retracting the scalp backward. Since the facial nerve also has a branch that goes to the occipital region, I think the posterior auricular artery or the occipital artery might be involved. Wait, no, the facial nerve's posterior auricular branch could be a possibility here. Alternatively, the greater occipital nerve from the cervical plexus might be a distractor. But wait, the facial nerve's postauricular branch supplies the occipital belly. Let me confirm that. The facial nerve (cranial nerve VII) does supply both bellies through different branches. The temporal branch for the frontal part and the postauricular (occipital) branch for the occipital belly. So the correct answer should be the facial nerve's postauricular branch. The other options might include the greater occipital nerve, which comes from the cervical plexus and innervates the occipitalis muscle, but I need to check if the occipital belly is considered part of the occipitofrontalis or if it's a separate muscle. Wait, the occipitofrontalis is a single muscle with two bellies connected by the galea aponeurotica. The occipital belly is part of this muscle, so it's innervated by the facial nerve's postauricular branch. The greater occipital nerve is from the cervical plexus and innervates the occipitalis muscle, which is a different muscle. So the answer is the facial nerve's postauricular branch. The wrong options could be other nerves like the greater occipital nerve, auriculotemporal nerve, or others. Let me make sure I'm not confusing the innervation. Yes, the facial nerve's postauricular branch is the correct one here.

**Core Concept**
The occipitofrontalis muscle, composed of frontal and occipital bellies connected by the epicranial aponeurosis, is innervated by the **facial nerve (CN VII)**. The occipital belly's specific supply is via the **postauricular branch** of the facial nerve, which also innervates the occipitalis muscle. This is a classic example of facial nerve distribution to scalp muscles.

**Why the Correct Answer is Right**
The **postauricular branch** of the facial nerve (CN VII) supplies the occipital belly of the occipitofrontalis muscle and the occipitalis muscle. This branch arises from the facial nerve's trunk after the stylomastoid foramen and runs posteriorly to innervate these muscles. Its role in occipital scalp movement (retraction) is critical for actions like pulling the scalp backward. The facial nerve’s

✓ Correct Answer: A. Posterior auricular nerve