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: Social & Preventive Medicine
Not a barrier method 
Select and explain. 
A. Condom, B. Today, C. Centchroman, D. Diaphragm
C: Centchroman
Answer: C: Centchroman 
Explanation: None