What happens to the ground spoilers if there is no weight on the main gear?

The correct understanding is that the ground spoilers cannot extend when there is no weight on the main gear. This is tied to the design and function of the ground spoilers, which are intended to assist in deceleration and control by increasing drag on the wings when the aircraft makes contact with the runway during landing.

Ground spoilers are equipped with weight-on-wheels (WOW) sensors that detect whether the aircraft's weight is applied to the landing gear. If the aircraft is airborne or there is insufficient weight on the wheels, the spoilers will not deploy. This design prevents the unintended extension of the spoilers during flight or prior to landing, ensuring safe aircraft handling.

Other options reflect scenarios that are not applicable: automatic deployment or deployment upon landing would not occur without sufficient weight on the main gear, and remaining in standby mode does not accurately represent the state of the spoilers in this situation since they simply do not extend at all when the weight condition is not met.