What basic strategy can reduce the incidence of HIV transmission?

Practicing sexual abstinence is recognized as a fundamental strategy in reducing the incidence of HIV transmission. This approach minimizes the risk of exposure to the virus, as HIV is most commonly transmitted through sexual contact with an infected person. By choosing to abstain from sexual activity, individuals eliminate the possibility of engaging in behaviors that could lead to the transmission of the virus, which significantly decreases the likelihood of contracting or spreading HIV.

The other choices—such as using separate toilets, sterilizing household utensils, and preventing direct casual contacts—do not effectively address the primary modes of HIV transmission, which predominantly occurs through sexual routes and sharing of needles or other blood products. While hygiene and limited exposure to blood are important in reducing other infections, they are not relevant to HIV transmission in the same way that sexual abstinence is.