What action should a bus driver take if they are unsure about a traffic signal?

Answer: B — Approach with caution and prepare to stop if necessary

If a bus driver is unsure about a traffic signal, approaching with caution and preparing to stop if necessary is the appropriate action. This approach prioritizes safety for the driver, passengers, and other road users. Traffic signals are critical for regulating the flow of vehicles and ensuring pedestrians have a safe environment to cross. By approaching cautiously, the driver can assess the situation further, allowing them to make a more informed decision on whether to proceed or stop. This tactic helps in avoiding potential accidents or conflicts at intersections. It reflects responsible driving behavior and acknowledges the complexity of navigating busy roadways where signals may malfunction or be unclear. Other options, such as continuing to drive without hesitation or ignoring the signal altogether, would pose significant risks by potentially leading to collisions or disregarding the rules of the road.