**Question:** The artery, which runs along the lower border of the posterior belly of digastric, is:

A. Buccalis artery
B. Superficial temporal artery
C. Sternocleidomastoid artery
D. Auriculotemporal artery

**Core Concept:**
The posterior belly of the digastric muscle is a small, triangular muscle located in the neck, which originates from the mastoid process of the temporal bone, passes through the mylohyoid groove, and inserts into the inferior margin of the mandible. The posterior belly of the digastric muscle is supplied by two arteries: the mylohyoid artery and the sternocleidomastoid artery.

**Why the Correct Answer is Right:**
The correct answer, C. Sternocleidomastoid artery, is related to the posterior belly of the digastric muscle. The sternocleidomastoid muscle is a larger muscle in the neck that runs from the sternum to the mastoid process of the temporal bone. The sternocleidomastoid artery is a branch of the common carotid artery that supplies blood to both the sternocleidomastoid muscle and the posterior belly of the digastric muscle.

**Why Each Wrong Option is Incorrect:**
A. Buccalis artery is a branch of the external carotid artery and supplies the buccinator muscle, which is located on the inner aspect of the cheek and is not related to the posterior belly of the digastric muscle.
B. Superficial temporal artery is a branch of the external carotid artery and supplies the skin and muscles of the temporal region but is not related to the posterior belly of the digastric muscle.
D. Auriculotemporal artery is a branch of the external carotid artery and supplies blood to the auricle and the temporalis muscle, not the posterior belly of the digastric muscle.

**Core Concept:**
The sternocleidomastoid artery is one of the branches of the common carotid artery, which is responsible for supplying blood to the muscles of the neck and the skin of the anterior neck.

**Why Each Wrong Option is Incorrect:**
A. Buccalis artery is a branch of the external carotid artery and supplies the buccinator muscle, which is not related to the posterior belly of the digastric muscle.
B. Superficial temporal artery is a branch of the external carotid artery and supplies the skin and muscles of the temporal region but is not related to the posterior belly of the digastric muscle.
C. Auriculotemporal artery is a branch of the external carotid artery and supplies the auricle and the temporalis muscle, not the posterior belly of the digastric muscle.

**Why the Correct Answer is Right:**
The correct answer, C. Sternocleidomastoid artery, is a branch of the common carotid artery. This artery supplies blood to the muscles of the neck, including the posterior belly of the digastric muscle, which is a part of the deep cervical fascicle of the accessory nerve and plays a role in swall