Which of the following practices helps prevent the spread of HIV?

Using condoms is a well-established practice that significantly helps prevent the transmission of HIV. Condoms act as a barrier during sexual intercourse, which reduces the risk of the virus being passed from one person to another. This protective measure is especially vital as HIV can be present in bodily fluids such as blood, semen, and vaginal secretions. When used correctly and consistently during all types of sexual activity, condoms can provide effective protection against not only HIV but also other sexually transmitted infections (STIs).

The other options do not contribute to HIV prevention. For example, sharing food or using public restrooms poses no risk of transmitting HIV, as the virus does not spread through casual contact or by sharing meals. Handshaking also does not facilitate the transmission of HIV, as it does not involve exposure to infected bodily fluids.