Cu ions released suppress sperm motility and the fertilising capacity of sperms. This is the principle behind which of the following contraceptive methods?

Multiload 375 has 375 ${\mathrm{mm}}^2$ of copper wire wound around its stem. It discharges copper ions which in turn inhibits the motility of the sperm.

Progesteron or in combination with estrogen inhibits and implantation as well as alter the quality of cervical mucus to prevent/retard entry of sperms. 

Implanon is an implant which discharges hormones.

 LNG-20 is a hormonal IUD.

 Depo-provera is an injection which administers hormones.