What does a flashing amber traffic light at an intersection indicate to drivers?

Answer: B — Slow down and proceed with caution.

A flashing amber traffic light signals to drivers that they should slow down and proceed with caution. This indication is meant to alert drivers that the intersection may be active or that there could be potential hazards ahead. The driver needs to be vigilant and prepared to react to any unexpected scenarios, such as pedestrians crossing or vehicles entering the intersection. In contrast, other options imply actions that are either more restrictive (such as stopping for turns) or allow for continuation at full speed, which would not encourage the necessary caution required in potentially busy or unpredictable situations. The emphasis when encountering a flashing amber light is to reduce speed and ensure safe navigation through the intersection.