Which of the following is a contraceptive?         a. Copper t         b. Condom         c. Diaphragm

All of the options provided, a. Copper T, b. Condom, and c. Diaphragm, are types of contraceptives.

a. Copper T: This is a type of intrauterine device (IUD) that is inserted into the uterus for long-term birth control.

b. Condom: This is a type of barrier method of contraception that is worn over the penis during sex to prevent pregnancy and reduce the risk of sexually transmitted infections.

c. Diaphragm: This is a shallow, dome-shaped cup made of silicone. It's inserted into the vagina to cover the cervix and prevent sperm from reaching an egg.

So, all of the above are contraceptives.