This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Disorders of Gastrointestinal System Including Diarrhea, Subject name: Pediatrics
[{'content': 'A 5-day-old term male neonate presents with delayed passage of meconium, abdominal distension and bilious vomiting. Barium enema and intestinal biopsy findings are shown below: What is the diagnosis? \nSelect and explain. \nA. Congenital aganglionic megacolon, B. Hyperophic pyloric stenosis, C. Cystic fibrosis, D. Intestinal malrotation', 'role': 'user'}, {'content': 'Answer: A \nExplanation: 1st picture shows narrow distal segment with dilated proximal segment of intestine in Ba enema. 2nd picture shows hyperophied nerve bundles between muscular layer & submucosa and enteric nerve plexuses lacking ganglion cells in H&E stain. Both the above findings are suggestive of Hirschsprung disease (Congenital aganglionic megacolon)', 'role': 'assistant'}]