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: Radiology
[{'content': 'Most sensitive test for metastatic deposit is: \nSelect and explain. \nA. Isotope scan, B. CT scan, C. Skeletal survey, D. Tomography', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. Isotope scan', 'role': 'assistant'}]