**Core Concept**
The nasal mucosa is a complex structure composed of epithelial, connective, and vascular tissues that lines the nasal cavity. It plays a crucial role in various functions, including olfaction, respiration, and filtration. The nasal mucosa is innervated by the trigeminal nerve, which provides a rich vascular supply to maintain its delicate functions.

**Why the Correct Answer is Right**
The nasal mucosa is primarily supplied by the sphenopalatine artery, a branch of the maxillary artery. This artery arises from the first part of the maxillary artery and enters the pterygopalatine fossa. The sphenopalatine artery then passes through the sphenopalatine foramen and reaches the nasal cavity, where it supplies the nasal mucosa. The rich vascular supply of the nasal mucosa is essential for maintaining its mucociliary clearance function and supporting the nasal cycle.

**Why Each Wrong Option is Incorrect**
**Option A:** The external carotid artery primarily supplies the skin and muscles of the face, neck, and scalp, but not the nasal mucosa.
**Option B:** The facial artery is a branch of the external carotid artery that supplies the face, but it does not directly supply the nasal mucosa.
**Option C:** The ophthalmic artery is a branch of the internal carotid artery that supplies the eye, but it does not directly supply the nasal mucosa.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the nasal mucosa is highly vascularized and plays a crucial role in maintaining mucociliary clearance. The sphenopalatine artery is the primary supplier of blood to the nasal mucosa, and its ligation can lead to nasal congestion and decreased olfactory function.

**Correct Answer:** C.