Which of these contraceptives doesn't belong with the others?

A) the pill
B) the diaphragm
C) the cervical cap
D) the sponge

The Pill

Common terminology for oral contraceptive pills, used for birth control and other hormonal-related treatments.

Diaphragm

A dome-shaped, flexible barrier that covers the cervix to prevent pregnancy.

Sponge

A porous material used for cleaning or absorbing liquids, or a simple aquatic sea animal from which the material is traditionally derived.