This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gall Bladder & Bile Ducts, Subject name: Surgery
[{'content': 'Which of the following is the initial investigation of choice for evaluation of a suspected case of gall stones? \nSelect and explain. \nA. Ultrasonography, B. CT Scan, C. MRI, D. ERCP', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Ultrasonography * Transabdominal ultrasonography is the initial imaging modality of choice in patients with suspected gall stones, as it is accurate, readily available, inexpensive and quick to perform", 'role': 'assistant'}]