Which of the following is an effective method for ensuring safety while backing?

Using a helper and checking blind spots is considered the most effective method for ensuring safety while backing a vehicle, especially for larger trucks or vehicles with limited visibility. When backing up, there are numerous blind spots that drivers cannot see using their mirrors alone. A helper can provide guidance and signal when it is safe to move, which greatly reduces the risk of accidents.

Additionally, checking blind spots helps to validate that the area behind the vehicle is clear of obstacles, pedestrians, or other vehicles. This dual approach—utilizing both a helper's assistance and a thorough check of blind spots—enhances overall situational awareness and safety when maneuvering in reverse.

Relying solely on mirrors, backing quickly, or using only rearview cameras do not provide the same level of safety and awareness. Mirrors can miss crucial areas, backing quickly increases the risk of losing control, and while rearview cameras can assist, they do not eliminate blind spots entirely and should not be the only factor in decision-making.