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': 'Vocal cord palsy is not caused by: \nSelect and explain. \nA. Vertebral secondaries, B. Left atrial enlargement, C. Bronchogenic carcinoma, D. Secondaries in mediastinum', 'role': 'user'}, {'content': 'Answer: A \nExplanation: (a) Vertebral secondaries(Ref. Scott Brown, 6th ed., 1/12/17)Superior and recurrent laryngeal nerves are not in close proximity to vertebrae.Rest of the given (mediastinal) conditions can cause left recurrent laryngeal nerve palsy.', 'role': 'assistant'}]