What typically causes an engine seizure in a motorcycle?

Answer: C — Not enough lubrication in the engine

An engine seizure in a motorcycle most commonly occurs due to not enough lubrication in the engine. Lubrication is critical for reducing friction between moving parts. Engine oil facilitates this by creating a protective film on surfaces, ensuring smooth operation. If the lubrication is inadequate—either from low oil levels, oil degradation, or a blockage—it can lead to excessive friction and overheating. This, in turn, can cause the internal components to expand or even weld together, resulting in a complete engine seizure, which means the engine can no longer rotate freely. While other factors like over-revving or issues with the fuel and ignition systems can contribute to engine problems, they are less directly responsible for a seizure compared to lack of lubrication. An effective lubrication system is essential for maintaining engine health and preventing catastrophic failures.