## Core Concept
The sensory supply of the vocal cords is primarily provided by branches of the vagus nerve (cranial nerve X), which is a key component of the autonomic nervous system. The vagus nerve divides into several branches that supply various structures in the neck, thorax, and abdomen. Specifically, the sensory innervation of the vocal cords is crucial for functions such as speech and swallowing.

## Why the Correct Answer is Right
The correct answer, **Recurrent Laryngeal Nerve**, is right because this nerve is responsible for providing sensory innervation to the vocal cords below the level of the vocal folds (or cords), as well as motor innervation to all the intrinsic muscles of the larynx except the cricothyroid. The recurrent laryngeal nerves are branches of the vagus nerve that loop around the subclavian artery on the right and the ductus arteriosus (ligamentum arteriosum) on the left, then ascend in the tracheo-esophageal groove to supply the larynx.

## Why Each Wrong Option is Incorrect
- **Option A: Internal Laryngeal Nerve** - This nerve provides sensory innervation to the part of the larynx above the vocal folds (or cords) but not to the vocal cords themselves. It is a branch of the superior laryngeal nerve, which in turn is a branch of the vagus nerve.
- **Option B: External Laryngeal Nerve** - This is primarily a motor nerve, supplying the cricothyroid muscle, and does not provide sensory innervation to the vocal cords.
- **Option D: Superior Laryngeal Nerve** - While this nerve does provide sensory innervation to the larynx, it is specifically the internal laryngeal nerve (a branch of the superior laryngeal nerve) that supplies the area above the vocal cords, not the vocal cords themselves.

## Clinical Pearl / High-Yield Fact
A key point to remember is that the sensory supply to the vocal cords is divided at the level of the vocal folds. The **internal laryngeal nerve** supplies the area above the vocal folds, while the **recurrent laryngeal nerve** supplies the area below the vocal folds. This distinction is crucial in clinical practice, particularly in procedures involving the larynx.

## Correct Answer: C. Recurrent Laryngeal Nerve