What is the function of a motorcycle’s rearview mirrors?

Answer: C — To provide visibility of traffic behind

The function of a motorcycle’s rearview mirrors is to provide visibility of traffic behind. This is crucial for safe riding, as it allows riders to be aware of their surroundings and the movements of vehicles or obstacles approaching from the rear. By having a clear view of what is happening behind them, motorcyclists can make informed decisions, such as when to change lanes or when to slow down, thereby enhancing their overall safety on the road. The other options focus on aspects that do not relate to the primary purpose of rearview mirrors. Weight reduction, aesthetic appeal, and acceleration do not contribute to the safety and visibility that mirrors provide, making option C the only relevant choice in the context of motorcycle operation and safety.