This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Surgery
[{'content': 'Colonic disease can be diagnosed by all except \nSelect and explain. \nA. Viual colonoscopy, B. Ba enema, C. Ba swallow, D. Ba follow through', 'role': 'user'}, {'content': 'Answer: C \nExplanation: .Indications of Barium swallow * Dysphagia due to motility disorder like achalasia cardia, diffuse oesophageal spasm. * Dysphagia due to mechanical causes like carcinoma, benign strictures and neoplasms, external compression. *Pharyngeal pouch and other diveicula. * GORD .ref:SRB&;s manual of surgery,ed 3,pg no 721', 'role': 'assistant'}]