**Core Concept**
The somatosensory area of the cerebral cortex is responsible for processing sensory information from the body, including touch, pressure, temperature, and pain. The representation of different body parts in this area follows a specific somatotopic map, with areas of the body that are more sensitive or have more nerve endings receiving more cortical representation.

**Why the Correct Answer is Right**
The correct answer has a small representation in the somatosensory area due to its relatively lower sensitivity and fewer nerve endings. This is in contrast to areas like the lips, fingers, and face, which have a large representation due to their high sensitivity and numerous nerve endings. The somatosensory area receives input from the dorsal column-medial lemniscus pathway, which conveys information from mechanoreceptors, thermoreceptors, and nociceptors.

**Why Each Wrong Option is Incorrect**
* **Option A:** Incorrect because the face and lips have a large representation in the somatosensory area due to their high sensitivity and numerous nerve endings.
* **Option B:** Incorrect because the fingers have a large representation in the somatosensory area due to their high sensitivity and numerous nerve endings.
* **Option C:** Incorrect because the genital area has a moderate representation in the somatosensory area, but not the smallest among the options.

**Clinical Pearl / High-Yield Fact**
The somatosensory area is responsible for processing sensory information from the body, and its representation follows a specific somatotopic map. This can be remembered using the mnemonic "FACE" (Fingers, Arms, Chest, Eyes), which represents the areas of the body with the largest representation in the somatosensory area.

**Correct Answer:** D