Which action neutralizes the stall warning horn if the gear is up on the ground?

The stall warning horn is designed to alert the pilot of an impending stall condition. In multi-engine aircraft, the squat switch plays a crucial role in the operation of the stall warning system. When the aircraft is on the ground and the landing gear is up, the squat switch is activated due to weight on the wheels, signaling to the stall warning system that the aircraft is not in a flight condition. As a result, this action neutralizes the stall warning horn, preventing false alerts while the aircraft is on the ground.

The operation of the squat switch is intended to ensure that stall warnings are only activated in flight, where they are relevant. While lowering the flaps or adjusting the gear selector may affect the aircraft's configuration and potentially its stall characteristics, they do not specifically address the stall warning system in the context of being on the ground with the gear up. Therefore, the activation of the squat switch is the effective action to stop the stall warning horn in this situation.