Final answer:
a.A flashing yellow light. The correct answer is a flashing yellow light. It indicates that drivers should slow down and proceed with caution at an intersection.
Step-by-step explanation:
The correct answer is a. A flashing yellow light.
A flashing yellow light at an intersection indicates that drivers should slow down and proceed with caution. This is a warning to be prepared for potential hazards or changes in traffic conditions.
For example, a flashing yellow light might be used at an intersection where there is construction, an obstruction, or a high pedestrian crossing volume. It is important to be cautious and alert while approaching such an intersection.