The correct option is B Subdermal implants
Hormonal contraceptives can be used in a variety of ways. They can be used in the form of pills, injections, implants, and skin patches. The duration of their usage depends on the type in which they have been used.
The implants are inserted subdermally (under the skin) by trained nurses or doctors. The implants are known to provide contraception for a period of 2-3 years if inserted once.
Pills contain oral administration of progestogen alone, or a combination of progestogen-estrogen. There are many different formulations or brands, but the average pack is designed to be taken over a 28- day cycle. Pills have to be taken for 21 days starting preferably within the first 5 days of menstrual cycle. Then a gap of 7 days has to be maintained (during which menstruation occurs), and then it has to be repeated in the same pattern till the female desires to prevent conception. This is considered to be short term.
Hormonal injections are to be taken once in 3 months. It is because the contraceptive effect of the injections sustains for approximately 3 months. It is also short term.
Skin patches have to be replaced after 28 days. It is also short term.