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': 'Investigation of choice for marking out calcification of an intracranial lesion is: September 2010 \nSelect and explain. \nA. CT Scan, B. MRI scan, C. USG, D. Contrast studies', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A: CT Scan', 'role': 'assistant'}]