**Core Concept**
Hirschsprung disease is a congenital condition characterized by the absence of **ganglion cells** in the distal bowel, leading to a functional obstruction. This condition is related to the **enteric nervous system** and its development. The absence of these cells affects the **motility** of the bowel.

**Why the Correct Answer is Right**
The correct answer is related to the absence of **ganglion cells** in the **myenteric** and **submucosal plexus** of the bowel, which are crucial for the **peristalsis** and relaxation of the intestinal muscles. This absence leads to a sustained contraction of the affected segment, causing obstruction.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because it does not directly relate to the primary cause of Hirschsprung disease.
**Option B:** Incorrect as it is not the primary issue in Hirschsprung disease.
**Option C:** Incorrect because because the disease is not primarily caused by this option.
**Option D:** Incorrect as the disease is specifically related to the absence of ganglion cells.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that Hirschsprung disease typically presents with **constipation**, **abdominal distension**, and **vomiting** in newborns.

**Correct Answer:** D. Absence of ganglion cells