The correct option is (b) LNG-20.
LNG-20 is a hormone-releasing intrauterine device (IUD) that contains levonorgestrel, a synthetic progestin hormone. It is used for long-term contraception and works by releasing a small amount of levonorgestrel into the uterus, which thickens cervical mucus, inhibits sperm movement, and thins the uterine lining, making it less receptive to implantation. This type of IUD is effective at preventing pregnancy and has the added benefit of reducing menstrual bleeding in many women.