The correct option is B Depo-provera
There are various ways in which unwanted pregnancy can be prevented. There are basically two methods of birth control. These are temporary and permanent methods. Temporary methods include emergency contraceptive pills, condoms, Intra-uterine devices, birth control pill hormones, etc. Permanent methods include vasectomy and tubectomy. Nonoxynol-9 is the spermicide used along with diaphragm to prevent unwanted pregnancy. Depo-provera is a birth control pill hormone which is given every 3 months in injectable form. It contains progestin hormone. It prevents ovulation. Today sponge is a contraceptive sponge consists of nonoxynol-9. It is inserted in the vagian to prevent conception. Thus, the correct answer is 'Depo-provera.'