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: Medicine
[{'content': "Most common cause of Thyroiditis is: \nSelect and explain. \nA. Reidl 's Thyroiditis, B. Subacute Thyroditis, C. Hashimoto's Thyroiditis, D. Viral Thyroiditis", 'role': 'user'}, {'content': "Answer: C \nExplanation: Answer is C (Hashimoto's Thyroiditis) Hashimotas thyroiditis, also called chronic lymphocytic thyroiditis, is the most common firm of thyroiditis.", 'role': 'assistant'}]