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': 'Laryngeal cartilage involvement, investigation of choice is - \nSelect and explain. \nA. CT, B. MRI, C. Radionuclide scan, D. X- ray', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]