## **Core Concept**
The sensory supply to the tongue involves multiple cranial nerves, each responsible for different aspects of sensation. The lingual nerve, a branch of the **mandibular division of the trigeminal nerve (CN V3)**, provides general sensation (touch, pressure, temperature) to the anterior two-thirds of the tongue. The **facial nerve (CN VII)**, through its chorda tympani branch, mediates taste sensation to the anterior two-thirds of the tongue. The **glossopharyngeal nerve (CN IX)** provides both general sensation and taste to the posterior third of the tongue. The **vagus nerve (CN X)**, through its internal laryngeal branch, provides sensation to the epiglottis and the base of the tongue.

## **Why the Correct Answer is Right**
The correct answer, , is the nerve primarily responsible for motor supply to the muscles of mastication, not sensory supply to the tongue. The **mandibular division of the trigeminal nerve (CN V3)** does contribute to the sensory supply of the tongue through its lingual nerve branch, which provides general sensation. However, the question seems to focus on the primary or direct sensory innervation specifically related to taste or general sensation of the tongue, where **CN V3** indirectly supports through the lingual nerve but is not the primary nerve associated with taste.

## **Why Each Wrong Option is Incorrect**
- **Option A:** The **facial nerve (CN VII)**, through its chorda tympani branch, provides taste sensation to the anterior two-thirds of the tongue, making it a correct association with sensory supply.
- **Option B:** The **glossopharyngeal nerve (CN IX)** provides both general sensation and taste to the posterior third of the tongue, directly contributing to the sensory supply.
- **Option D:** The **vagus nerve (CN X)** provides sensation to the epiglottis and the base of the tongue, contributing to the sensory supply.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that the sensory innervation of the tongue is crucial for functions like taste and general sensation. The **lingual nerve** (a branch of **CN V3**) provides the afferent (sensory) innervation to the anterior two-thirds of the tongue for general sensation, while **CN VII** and **CN IX** are involved in the taste sensation. Clinical correlation includes understanding that damage to these nerves can result in alterations in taste and sensation.

## **Correct Answer:** .