What would trigger an anti-skid warning during landing?

The correct answer is related to insufficient traction during landing. Anti-skid systems are designed to prevent the wheels from locking up during braking, which can cause loss of control and increased stopping distances. If the aircraft experiences insufficient traction — for example, due to wet or icy runway conditions or if the brakes are applied too aggressively — the anti-skid system will engage to modulate braking pressure and maintain wheel rotation. In doing so, it helps reduce the risk of skidding.

When inadequate traction is detected, the anti-skid warning is triggered to alert the pilots that the system is actively managing braking to prevent wheel lock-up. This function is crucial for maintaining control during the landing roll, especially when conditions are less than optimal.

Other options involve factors that typically do not directly trigger an anti-skid warning. Exceeding landing weight limits and incorrect landing gear positioning may affect overall aircraft performance and safety, but they do not specifically relate to the anti-skid system's operation. Improper flap extension might impact lift and drag characteristics, but it does not explicitly interact with the traction management aspect of the braking system.