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': 'The density of the parafollicular cells or C- cells in the thyroid gland is maximum at the: \nSelect and explain. \nA. Isthmus, B. Posterior pa, C. Juncture of the upper ? and lower 2/3 of the gland, D. Upper ? of the gland', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The parafollicular cells or C- cells in the thyroid gland is present in all pas of the thyroid gland. Their density is greatest in the juncture of the upper one-third and lower two-thirds of the gland. Ref: Harrison, E-18, P-2912', 'role': 'assistant'}]