What is a potential risk when backing a vehicle?

Answer: C — Lack of visibility

When backing a vehicle, lack of visibility is a significant risk. Large vehicles, such as trucks and buses, often have large blind spots that make it difficult for the driver to see obstacles, pedestrians, or other vehicles behind them. This limited visibility can lead to dangerous situations, including collisions or running over objects or individuals that are out of the driver's line of sight. Recognizing the need for additional caution while backing up is crucial. Drivers should always check their mirrors, use a spotter when available, and take their time to ensure the path is clear before moving in reverse. This approach helps mitigate the risks associated with poor visibility, ensuring safer maneuvering. In contrast, high speeds and avoiding turns do not directly relate to the risks of backing up since the action is typically done at low speeds and often does not involve turns. Additionally, stating "none of the above" would not apply as lack of visibility is a relevant risk factor in this scenario.