This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Contraceptives, Subject name: Gynaecology & Obstetrics
Not a barrier contraceptive: 
Select and explain. 
A. Diaphragm, B. Centchroman, C. Condom, D. Today
B: Centchroman
Answer: B: Centchroman 
Explanation: Ans. is b, i.e. CentchromanRef: 15th/ed, p222Barrier Methods include:* Condoms (for male use)* Diaphragms (for female use) - Types1. Femshield (female condom)2. Today contraceptive/vaginal sponge3. Vaginal diaphragm/cervical capBesides these spermicidal agents like nonoxynol 9, octoxynol, and menfegol can be added to any of the above barrier contraceptive, to increase its effectiveness.