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
Mechanism of action of Calcitriol is: 
Select and explain. 
A. Decreased calcium resorption calcium from bone, B. Increase calcium absorption from intestine, C. Decreased calcium absorption from kidney, D. Decrease calcium absorption from intestine
B: Increase calcium absorption from intestine
Answer: B: Increase calcium absorption from intestine 
Explanation: Calcitriol is a synthetic version of Vitamin D3 used to treat calcium deficiency with hypoparathyroidism Bone-calcitriol increases resorption of calcium from bone.kidney-it increases calcium reabsorption in the distal tubule.intestine-it promotes intestinal absorption of calcium (Ref.Essentials of medical pharmacology TD Tripathi 7th edition page no.338)