What will happen to the THS if both the green or yellow hydraulic system fail?

When both the green and yellow hydraulic systems fail on an A320, the Thrust Reverser System (THS) will not move. The THS relies on hydraulic power from these systems for functionality and control. In the event of a complete hydraulic failure in both systems, the ability to deploy or retract the THS is lost, as hydraulic pressure is essential for its operation. This results in the THS being inoperative and unable to change its position.

The inability of the THS to move stems from its dependence on hydraulic power, and without this power, there is no mechanism to actuate its components. Therefore, the system will remain in a neutral position, but since the correct option specifies that the THS simply will not move, it accurately reflects the consequences of the hydraulic system failure.