Final answer:
The federal Hours of Service regulations (c) regulate the number of hours a driver can work, ensuring road safety by controlling driving time and preventing fatigue.
Step-by-step explanation:
The correct answer to the question regarding the federal Hours of Service regulations is (c) They regulate the number of hours a driver can work. The federal regulations are in place to ensure safety by controlling the amount of time a driver can legally drive and work during a given period. These rules apply to commercial vehicle drivers to prevent fatigue-related accidents on the roads. The other options provided in the question are incorrect as the regulations do not exclusively apply to commercial vehicles (a), they may not be identical to Alberta's regulations (b), and they certainly do apply to long-haul drivers (d).