What does it mean if a traffic signal is out?

Answer: B — Treat it as a four-way stop

When a traffic signal is out, it means that the signal is not functioning and, as a result, it is treated as though it were a four-way stop. This requires all drivers approaching the intersection to come to a complete stop and yield to any vehicles or pedestrians that may have the right of way. This rule helps maintain order and safety at intersections where the normal traffic signals are not operational, providing clear guidelines on how to proceed without causing confusion or accidents. The other options do not align with standard traffic procedures when a signal is out. Treating it as a yield sign is incorrect because it does not provide the same level of caution required at an intersection. Continuing to drive as usual could lead to dangerous situations, as drivers may not be aware of each other without signals to guide them. Calling 911 for assistance is typically unnecessary and could divert emergency resources from more critical situations, as the proper course of action is to follow the established rules of the road for non-functioning signals.