This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous (Gynae), Subject name: Gynaecology & Obstetrics
[{'content': 'Tamoxifen is: \nSelect and explain. \nA. Non steroidal antiprogesterone, B. Non steroidal antioestrogenic, C. Synthetic progestogen norethindrone, D. Competitive inhibitor of the 5 a - reductase', 'role': 'user'}, {'content': "Answer: B \nExplanation: (Non steroidal antioestrogenic) (306-Shaw's 13th) (186-S14th)* Tamoxifen - non steroidal antioestrogenic drug* Clomiphene citrate - non steroidal anti oestrogens related to the diethylstilbestrol (DES)* Mifepristone - Synthetic antiprogesterone* Anti androgens - Cyproterone acetate, Spironolactone, Flutamide, FinastJeride {Inhibitor of 5a- reductase)", 'role': 'assistant'}]