Which of the following is an important safety practice when changing a flat tire?

Ensuring the vehicle is on a flat surface is crucial for safety when changing a flat tire. This practice prevents the vehicle from rolling, which could lead to serious injuries or an accident. A flat surface helps stabilize the vehicle, allowing the individual changing the tire to work more safely and effectively. It reduces the risk of the jack slipping or the vehicle tipping, which could lead to harm to the person changing the tire or others nearby.

Choosing to change a tire in adverse weather conditions, such as rain, can increase the risk of accidents and make the process more difficult and hazardous. Using tools without gloves can lead to injuries caused by sharp edges or pinch points. Ignoring traffic around the vehicle creates a dangerous situation, as it puts both the individual changing the tire and passing motorists at risk. Thus, ensuring the vehicle is on a flat surface stands out as a vital safety measure in this context.