This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Renal physiology, Subject name: Physiology
True about calcium in kidney is 
Select and explain. 
A. Most reabsorption occurs in DCT, B. Major regulating factor is parathormone, C. Parathormone decreases calcium absorption, D. Increased plasma phosphate decreases calcium resorption
B: Major regulating factor is parathormone
Answer: B: Major regulating factor is parathormone 
Explanation: Parathormone secreted by parathyroid glands regulates the blood calcium level. Ref: guyton and hall textbook of medical physiology 12 edition page number: 495,496,497