________ are the most effective means of preventing STIs during heterosexual contact.

A) Pills
B) IUDs
C) Depo-Provera and Norplant
D) Condoms

Condoms are the most effective means of preventing sexually transmitted infections (STIs) during heterosexual contact. They create a physical barrier and can help reduce the risk of transmitting or acquiring STIs, including HIV. Other forms of contraception such as pills, IUDs, Depo-Provera, and Norplant do not provide protection against STIs.