This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Gynaecology & Obstetrics
First line of Rx of osteoporosis in postmenopausal women 
Select and explain. 
A. Estrogen, B. Bisphosphonates, C. Raloxifene, D. Ullipsistal
B: Bisphosphonates
Answer: B: Bisphosphonates 
Explanation: REF : SHAW GYNECOLOGY REF REF :