**Core Concept**
Neural crest cells are embryonic cells that migrate from the dorsal neural tube and give rise to various structures, including enteric nervous system neurons in the gut. Failure of their migration leads to impaired development of the enteric nervous system, a key factor in gastrointestinal motility disorders.

**Why the Correct Answer is Right**
Congenital megacolon (Hirschsprung disease) results from the absence of ganglion cells in the distal colon due to failure of neural crest cell migration during embryogenesis. These cells normally colonize the entire length of the gut; their failure to migrate into the distal colon leads to aganglionic segments, causing obstructive constipation at birth. This is a classic example of neural crest cell migration defect.

**Why Each Wrong Option is Incorrect**
Option A: Albinism is due to defects in melanin synthesis, primarily involving melanocyte development, not neural crest cell migration. Melanocytes originate from neural crest but albinism reflects pigment deficiency, not migration failure.
Option C: Odontomes are benign dental malformations arising from abnormal odontogenic tissue development, not neural crest migration defects.
Option D: Adrenal tumors arise from neural crest-derived cells, but their development is not linked to migration failure; rather, they result from dysregulation of adrenal hormone production.

**Clinical Pearl / High-Yield Fact**
Hirschsprung disease is the most common congenital gastrointestinal disorder due to neural crest cell migration failure, and diagnosis is confirmed by rectal biopsies showing absence of ganglia. Early surgical intervention (pull-through procedure) is critical to prevent bowel obstruction.

✓ Correct Answer: B. Congenital megacolon