This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: ENT
[{'content': 'A suspected case of Dysphagia lusoria should be best investigated by \nSelect and explain. \nA. HRCT, B. Spiral CT, C. MRA, D. DSA', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Barium swallow, bronchoscopy, or angiographies are investigations to diagnose but angiography is diagnostic. Ref : ENT textbook by Dhingra 6th edition Pgno : 447', 'role': 'assistant'}]