More than half of all crashes:

The correct response indicates that a significant portion of motorcycle crashes involves riders who have relatively little experience, specifically those who have been riding for less than six months. This highlights the importance of experience and familiarity with handling a motorcycle, which is critical for safe riding. Inexperienced riders may lack the skills to manage complex traffic situations, respond appropriately to unexpected events, or execute maneuvers safely, increasing their risk of being involved in a crash.

Riding experience is key in developing reflexes and sound judgment needed on the road. It's essential for new riders to undergo proper training and gain enough time on their motorcycle to build confidence and skills before they face more challenging riding conditions.

The other options, while they may describe factors that can contribute to crashes under certain circumstances, do not emphasize the impact of rider experience as strongly as the chosen answer does. For instance, while speed and nighttime riding can both be significant factors in crashes, they are not necessarily indicative of the level of risk tied to a rider’s inexperience. Similarly, worn tires represent a specific mechanical issue that affects safety but again does not directly relate to the experience level of the rider.