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: Physiology
[{'content': 'Osteoclasts are inhibited by: \nSelect and explain. \nA. Parathyroid hormone, B. Calcitonin, C. 1,25-dihydroxycholecalciferol, D. Tumor necrosis factor', 'role': 'user'}, {'content': "Answer: B \nExplanation: Calcitonin inhibits bone resorption by direct action on osteoclasts. Ref: Ganong's Review of Medical Physiology, 21st Edition, Page 397", 'role': 'assistant'}]