This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Anatomy
[{'content': 'Investigation of choice for hydatid disease is \nSelect and explain. \nA. CT scan, B. ELISA, C. Biopsy, D. USG', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Diagnosis is confirmed by Serological tests for antibodies like ELISA Immunoblot Arc-5 IHA', 'role': 'assistant'}]