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 to diagnose H-type tracheoesophageal fistuala is: \nSelect and explain. \nA. X-ray, B. Esophagoscopy, C. Tracheobronchoscopy, D. CT scan', 'role': 'user'}, {'content': 'Answer: B \nExplanation: (Refer: OP Ghai’s Essentials of Pediatrics, 8th edition, pg no: 176)\n\nThe most reliable method of establishing the diagnosis of H type fistula is by a prone tube video esophagogram. Bronchoscopy with esophagoscopy will confirm the presence of a fistula\nEsophagography and/or cine esophagography, or bronchoscopy and simultaneous methylene blue administration confirmed the diagnosis of H-type TEF.\nAlthough cine esophagography is highly effective in demonstrating H-type TEF today, bronchoscopy must be used in every patient suspected of having fistula, especially when the radiological methods fail.', 'role': 'assistant'}]