This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Larynx, Subject name: ENT
[{'content': 'Following is/are the causes of a chronic cough with noncontributory chest radiograph? \nSelect and explain. \nA. Asthma, B. Post nasal drip, C. GERD, D. All the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: 90% of patients who have a chronic cough and a normal or noncontributory chest radiograph belong to one of the following causes:Use of an angiotensin-conveing enzyme inhibitor;Post -nasal drainage;Gastroesophageal reflux; andAsthmaRef: PL Dhingra, Diseases of Ear, Nose & Throat, 7th edition', 'role': 'assistant'}]