The correct option is B 1, 2 and 4 only
Intra-Uterine Devices (IUDs) are small devices that are inserted inside the uterus to interrupt the process of fertilisation and pregnancy. These methods of contraceptives increase phagocytosis of sperms inside the uterus, suppress sperm motility, make the uterus unsuitable for implantation, and make the cervix hostile for sperms. CuT, Cu7, and Multiload 375, all belong to the second generation Intrauterine Devices (IUDs), or copper releasing IUDs. Copper-containing IUDs have a strong anti-fertility effect, are easy to fit, and smaller in size. Advantages of copper-containing devices are that they have low side effects and bleeding, increased contraceptive effectiveness, and high durability.
LNG- 20 is a hormone-releasing IUD, which belongs to the third generation IUDs (Levonorgestrel releases 20 micrograms per day). It causes thinning of the uterine lining (endometrial atrophy) and inhibits implantation along with promoting sperm phagocytosis.