Final answer:
Bus drivers should heed 'Truck Advisory' speed limits when descending steep hills and must pull over to check their brakes if necessary. The correct option is d. b. and c. are correct.
Step-by-step explanation:
The question you are asking relates to the best practices that bus drivers should follow when navigating certain road conditions, specifically steep hills. To answer your question:
Bus drivers should heed 'Truck Advisory' speed limits when traveling down steep hills and pull over and check their brakes when required. Therefore, the correct answer is d. b. and c. are correct.
While avoiding steep hills altogether might seem like a safe choice, it is not always practical or possible. Instead, bus drivers are trained to handle such situations with caution. Following truck advisory speed limits helps them maintain control of the vehicle during the descent, and checking their brakes ensures the safety of the bus before, during, and after traveling down a steep hill, especially if there has been heavy use of the brakes which could lead to overheating and failure.