Assertion (A): Pills are taken daily for a period of 21 days to prevent pregnancy.

Reason (R): Pills inhibit ovulation and implantation as well as alter the quality of cervical mucus to prevent/retard the entry of sperms.

Both A and R are true, and R is the correct explanation of A.

The correct answer is Option (1) –Both A and R are true, and R is the correct explanation of A.

Pills have to be taken daily for a period of 21 days starting preferably within the first five days of menstrual cycle. After a gap of 7 days (during which menstruation occurs) it has to be repeated in the same pattern till the female desires to prevent conception.

They inhibit ovulation and implantation as well as alter the quality of cervical mucus to prevent/retard entry of sperms. Pills are very effective with lesser side effects and are well accepted by the females.

Saheli –the new oral contraceptive for the females contains a non-steroidal preparation. It is a ‘once a week’ pill with very few side effects and high contraceptive value .The world's first non steroidal oral contraceptive pills developed under the name 'Saheli' were introduced by the Central Drug Research Institute, Lucknow in 1991.