This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
[{'content': "True statement regarding Hirschsprung's disease- \nSelect and explain. \nA. Giant ganglia are present, B. Mucosa is involved and show foldings, C. Manometry excludes the disease, D. Rectal biopsy is contraindicated in infants.", 'role': 'user'}, {'content': "Answer: C \nExplanation: Anorectal manometry is a useful screening procedure for the diagnosis of Hirschsprung's disease. A normal response in course of manometric evaluation precludes the diagnosis of Hirschsprung's disease.\nHowever, the confirmation of diagnosis in case of Hirschsprung's disease is done by rectal biopsy.\n\nPathogenesis of Hirchsprung disease\n\nThe enteric neuronal plexuses develop from neural crest cells, which migrate into the bowel wall during develop\xadment, mostly in a cephalad to caudad direction.\nHirschsprung disease results when the migration of neural crest cells arrests at some point before reaching the anus → inappropriate premature death.\nThis produces an intestinal segment that lacks both Meissner submucosal and Auerbach myenteric plexus.\nLoss of enteric neural coordination leads to functional obstruction and intestinal dilation proximal to the affected segment.", 'role': 'assistant'}]