Which of the following risk behaviors is most likely to cause harm or injury to others?

Drinking and driving is the behavior most likely to cause harm or injury to others because it significantly impairs a person's ability to operate a vehicle safely. Alcohol consumption affects reaction times, judgment, and coordination, which can lead to accidents that not only endanger the driver but also passengers, pedestrians, and other drivers on the road. When individuals choose to drive under the influence, they increase the risk of crashes, potentially resulting in severe injuries or fatalities to themselves and others.

While texting while driving also poses serious risks as it distracts the driver, drinking and driving is particularly dangerous due to the profound effects of alcohol on cognitive and motor functions. Sharing needles poses risks primarily to the individual due to the spread of infections, and allergic reactions typically result in harm only to the person experiencing the reaction. Thus, among these options, drinking and driving stands out as the behavior with the highest potential to harm others.