Which of the following maintenance issues could lead to a motorcycle emergency?

Tire failure and engine seizure can indeed lead to significant motorcycle emergencies. The tires are critical for maintaining traction and stability while riding; a failure can result in loss of control, especially at high speeds or in turns. If a tire blows out, the rider may struggle to maintain balance, increasing the risk of an accident.

Engine seizure, on the other hand, occurs when the engine's moving parts become damaged due to inadequate lubrication or overheating. This situation can lead to sudden and complete loss of power, making it impossible to maintain control of the motorcycle. In both cases, the rider could be faced with a sudden emergency that demands quick reactions to avoid a crash or minimize the danger.

While other options mention issues like low oil or dirty filters, which are serious maintenance concerns, they may not lead to an immediate emergency in the same way that tire failure and engine seizure would.