This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Gynaecology & Obstetrics
Tamoxifen is : 
Select and explain. 
A. Non steroidal antiprogesterone, B. Non steroidal antioestrogenic, C. Synthetic progestogen norethindrone, D. Competitive inhibitor of the 5alpha-reductase
B: Non steroidal antioestrogenic
Answer: B: Non steroidal antioestrogenic 
Explanation: Non steroidal antioestrogenic