## **Core Concept**
The **trigeminal nerve**, also known as the **fifth cranial nerve (Vth cranial nerve)**, is a mixed nerve responsible for sensory supply to the face and motor supply to the muscles of mastication. It has three main divisions.

## **Why the Correct Answer is Right**
The three main divisions of the trigeminal nerve are:
- **Ophthalmic division (V1)**: responsible for sensory innervation of the eye and surrounding area.
- **Maxillary division (V2)**: responsible for sensory innervation of the middle third of the face including the upper lip, palate, and nasal cavity.
- **Mandibular division (V3)**: responsible for sensory innervation of the lower third of the face including the lower lip, and motor innervation to the muscles of mastication.

## **Why Each Wrong Option is Incorrect**
- **Option A:** Ophthalmic (V1) is indeed a division of the trigeminal nerve.
- **Option B:** Maxillary (V2) is also a division of the trigeminal nerve.
- **Option D:** Mandibular (V3) is a division as well.

## **Clinical Pearl / High-Yield Fact**
A key clinical correlation is **trigeminal neuralgia**, a condition characterized by intense pain in one or more divisions of the trigeminal nerve. Understanding the divisions is crucial for diagnosis and treatment.

## **Correct Answer:** .