Final answer:
At the start of each year, it is crucial to check a snowmobile's brake system, lights, and throttle to ensure safe operation. These checks are important for the maintenance and performance of the vehicle.
Step-by-step explanation:
At the start of every year, it is important to perform a safety check on a snowmobile. The parts that should be thoroughly checked include the brake system, lights, and throttle to ensure they are functioning properly. Checking these parts is crucial for maintaining the safety and performance of the snowmobile.
Option (a) is incorrect because snowmobiles are not maintenance-free; they require regular checks and upkeep. Option (c) about seat cushion and handlebars and option (d) regarding windshield wipers and radio are less critical compared to the brake system, lights, and throttle, which are essential for safe operation of the vehicle.
It is also a good practice to review the owner's manual for specific maintenance recommendations and to inspect other components such as skis, track, suspension, fluids, and the engine to ensure all parts are in good working order.