What is a significant risk associated with U-turns?

Making U-turns poses a significant risk primarily because drivers may not see motorcyclists while executing the maneuver. This lack of visibility is particularly concerning, as motorcycle riders are smaller and less conspicuous than larger vehicles. When a driver decides to make a U-turn, they may focus primarily on oncoming traffic, pedestrians, and obstacles rather than checking for motorcycles that might be approaching from behind or at an angle.

This risk is compounded by the fact that a motorcycle can often be in a position where it is difficult for a driver to notice it, especially if the motorcycle is moving at a speed that does not allow for quick reactions. This scenario can lead to dangerous collisions if a driver turns into the path of an oncoming motorcycle, as the rider may not have enough time to react or brake to avoid the accident.

Other options touch on various aspects of U-turns but fail to address the critical factor of visibility that makes option B the most valid concern for motorcyclists.