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': 'Parathyroid gland can he assessed by: \nSelect and explain. \nA. Thallium scan, B. Technetium scan, C. Gallium scan, D. Thallium technetium substraction scan', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. Thallium technetium substraction scan', 'role': 'assistant'}]