Let's evaluate the given options one by one:
1. Lippe's loop: This is a type of intrauterine device (IUD) and is used for birth control. Correct.
2. Vaults: This is not a recognized type of IUD. It is not used for contraception and does not fall under IUD classification. Incorrect.
3. Multiload 375: This is a type of intrauterine device. It is commonly used for contraception and is recognized in IUD classifications. Correct.
4. LNG-20: This is a type of intrauterine system (IUS) containing the hormone levonorgestrel, used as a contraceptive device. Correct.
5. Diaphragms: Diaphragms are barrier methods of contraception and are not IUDs. Incorrect.
Thus, the correct intrauterine devices are A (Lippe's loop), C (Multiload 375), D (LNG-20). The correct answer is Option B.