Which one of the following is an example of hormone releasing IUD?

The correct option is C LNG $20$
All the options given are IUDs, but their modes of action are different.

LNG-20 is a hormone releasing IUD. It releases levonorgestrel, a progestin (synthetic hormone similar to progesterone) and makes the uterus unfavorable for implantation, as well
as thickens the cervical mucus.

Cu7, Cu T, Multiload 375 are copper-releasing IUDs. They release copper ions and help in contraception by decreasing sperm motility.