IUDs stand for:

The correct answer is Option (4) → Intra Uterine Devices

IUDs are Intra Uterine Devices. ‘Intra’ means ‘inside’, and these are small devices placed inside the uterus to prevent pregnancy. Doctors or trained nurses insert them through the vagina. There are three kinds:

    non-medicated IUDs, e.g. Lippes loop
    copper-releasing IUDs, e.g. CuT, Cu7, Multiload 375
    hormone-releasing IUDs, e.g. Progestasert, LNG-20

IUDs increase the destruction of sperms (phagocytosis) inside the uterus. The copper ions released reduce the movement and fertilising capacity of sperms. The hormone-releasing IUDs also make the uterus unsuitable for implantation.

(4) Intra Uterine Devices — Correct. Both words fit: Intra (inside) the uterus, and Devices, objects placed there by a doctor. An IUD is a device, not a stage of development.

NCERT Extract:
Population Stabilisation and Birth Control – …