This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Contrast Agents, Subject name: Radiology
[{'content': 'Following RAIU studies demonstrate \nSelect and explain. \nA. Graves Disease, B. Toxic Adenoma, C. MNG, D. Lingual Thyroid', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]