Which action is not an effective method for preventing HIV transmission?

The option indicating sharing needles for drug use is not an effective method for preventing HIV transmission because sharing needles directly exposes individuals to the blood of an infected person, significantly increasing the risk of transmitting HIV and other blood-borne viruses. When a needle is shared, the virus can easily transfer from an infected person to another person, making this practice highly unsafe.

In contrast, using condoms during intercourse is a well-established method for reducing the risk of HIV transmission, as they act as a barrier that prevents the exchange of bodily fluids. Regular HIV testing is important for early detection and treatment of HIV, but it is not a preventive action; rather, it helps individuals understand their status and make informed decisions about their health. Practicing safe sex encompasses various strategies, including the use of condoms and limiting the number of sexual partners, which all contribute to lower transmission rates of HIV. Overall, avoiding behaviors that put individuals in contact with infected blood, like sharing needles, is critical in preventing HIV transmission.