What should a motorcyclist do when riding on gravel roads?

Answer: B — Reduce speed and avoid sudden throttle or brake changes.

Reducing speed and avoiding sudden throttle or brake changes is crucial when riding on gravel roads due to the unpredictable nature of loose surfaces. Gravel can decrease traction significantly, and maintaining control becomes more challenging at higher speeds. By reducing speed, a motorcyclist allows themselves to react better to any changes in the road's condition, minimizing the risk of losing control. Sudden changes in throttle or brakes can lead to skidding or sliding, especially on gravel, where stability is compromised. Smooth and gentle inputs are key to navigating these surfaces safely.