## **Core Concept**
The intrinsic muscles of the tongue are responsible for changing its shape and are crucial for functions like speech and swallowing. These muscles are derived from the **occipital somites**, also known as the somites of the occipital region.

## **Why the Correct Answer is Right**
The intrinsic muscles of the tongue, including the longitudinal, transverse, and vertical muscles, are derived from the **third and fourth occipital somites**. These somites give rise to the muscles that are intrinsic to the tongue, which are essential for its movements and shape changes. The development of these muscles is closely related to the embryological origins of the tongue.

## **Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because the intrinsic muscles of the tongue do not originate from the **first pharyngeal arch**, which primarily contributes to the formation of muscles involved in mastication (chewing).
* **Option B:** This option is incorrect because the **second pharyngeal arch** (hyoid arch) primarily gives rise to muscles of facial expression, not the intrinsic muscles of the tongue.
* **Option C:** This option might seem plausible but is incorrect because, although the **third pharyngeal arch** does contribute to some tongue muscles, the intrinsic muscles specifically are derived from occipital somites.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that the **intrinsic and extrinsic muscles of the tongue** are crucial for its function and are innervated by the **hypoglossal nerve (CN XII)**, except for the palatoglossus, which is innervated by the vagus nerve (CN X) via the pharyngeal plexus.

## **Correct Answer:** D. Occipital somites.