This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Pharmacology
[{'content': 'Which of the following is fastest calcium lowering agents \nSelect and explain. \nA. Calcitonin, B. Plicamycin, C. Etidronate, D. Zoledronate', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Refer CMDT 2010/801 Bisphoshonates are the treatment of choice for hypercalcemia of malignancy but require 48-72 hours before reaching full therapeutic effect Calcitonin may be helpful to treat hypercalcemia before the onset of action of bisphoshonates', 'role': 'assistant'}]