What condition must be met for the GLD's to automatically deploy?

The automatic deployment of the Ground Lift Devices (GLDs) on the Canadair Regional Jet (CRJ) is contingent upon multiple conditions being satisfied, making "All of the above" the correct choice. For the GLDs to deploy automatically, it is necessary that both thrust levers are at idle or less, indicating that the aircraft is in a deceleration mode suitable for landing. Additionally, the condition of "Weight on Wheels" is crucial, as it confirms that the aircraft has made contact with the runway, another indicator that deployment is appropriate. Finally, the wheel spin-up condition ensures that the wheels are rotating, verifying that the aircraft is engaging in the landing phase rather than still being in the air. All these factors work in conjunction to ensure safe and effective operation, reflecting the aircraft's design intent for managing lift upon landing.