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: ENT
[{'content': 'High tracheostomy is indicated in - \nSelect and explain. \nA. Carcinoma, B. TB, C. Tetanus, D. Diphtheria', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]