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: Social & Preventive Medicine
[{'content': 'True about Iodine deficiency disorder \nSelect and explain. \nA. Exclusively found in Himalayan goitre bell, B. Only monitered by blood thyroid test, C. Includes only goitre, D. Goitre prevalence of >10% in an area is considered as endemicity', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]