It contains synthetic progesterone.
It decreases risk of cancer.
It contains centchroman.
It is taken thrice in a week.
Saheli is the only contraceptive pill that is non-hormonal. It contains ormeloxifene, which is also known as centchroman. It is a selective estrogen receptor modulator which acts on estrogen receptor. It is a non-steroidal oral contraceptive pill. So, the correct answer is 'It contains centchroman'.