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: Radiology
[{'content': 'Diffuse esophageal dilatation on barium swallow is seen in – a) Achlasiab) Trypanosomiasisc) Etidronate therapyd) Scleroderma \nSelect and explain. \nA. ac, B. ab, C. ad, D. bc', 'role': 'user'}, {'content': "Answer: B \nExplanation: Diffuse esophageal dilatation is seen in -\ni) Primary achalasia Achalasia cardia\nii) Secondary achalasia Chaga's disease (trypanosomiasis), MEN, Triple 'A' (Allgrove's) syndrome, cancer invading LES (Pseudoachalasia).", 'role': 'assistant'}]