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
Which of the following drugs causes osteoporosis on long term use 
Select and explain. 
A. Etidronate, B. Prednisolone, C. Phneytion, D. Calcitriol
B: Prednisolone
Answer: B: Prednisolone 
Explanation: Refer KDT 7/e p 293 Etidronate and phneytoin cause osteomalacia whereas calcitriol is used in treatment of osteoporosis