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: Unknown
[{'content': 'Best investigation for Diffuse Esophageal Spasm : \nSelect and explain. \nA. Enteroscopy, B. Manometry, C. Barium enema, D. Barium meal follow through', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans- B Manometry For Motility disorders:: First line is UGIE IOC IS Manometry For GERD::1st line is UGIE IOC :24 hr ambulatory pH measurement.', 'role': 'assistant'}]