This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: ULTRASOUND, Subject name: Radiology
[{'content': 'Investigation of choice to visualize gallbladder pathologies: \nSelect and explain. \nA. CT, B. USG, C. Plain X-Ray, D. MRCP', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ultrasound is the Investigation of Choice for most Gall Bladder pathologies like Acute Cholecystitis, Gb polyp, Gb calculus.', 'role': 'assistant'}]