What does an added lane signify for drivers?

Answer: B — Watch for other vehicles changing lanes

An added lane indicates that drivers should be vigilant and aware of their surroundings, particularly regarding other vehicles. This situation often leads to drivers changing lanes to utilize the newly available space. Therefore, staying attentive and prepared for others who may be adjusting their positions on the road is crucial. By being aware of surrounding traffic, especially during a lane addition, drivers can enhance safety and prevent potential collisions or accidents. While other options touch on important aspects of driving behavior, the emphasis here is on the importance of awareness and readiness to react to the actions of other drivers in response to the added lane.