What action should be taken regarding the transponder during a controlled ejection?

Setting the transponder to 7700 during a controlled ejection is the correct action because this code is universally recognized as the emergency transponder code. When a pilot sets the transponder to 7700, it alerts air traffic control and other aircraft that there is an emergency situation. This visibility is critical in ensuring that immediate assistance can be provided and that ground and air operations can respond appropriately. In scenarios like a controlled ejection, where the pilot may need to evacuate the aircraft quickly and potentially enter a life-threatening situation, broadcasting the emergency status enhances the chances of receiving timely help.

By contrast, the other options do not fulfill the same role as 7700. Setting the transponder to 7500 indicates a hijacking, which does not apply to an emergency evacuation. Setting it to 8000 generally signifies a change in squawk for visual flight rules (VFR) flying, and turning it off would not effectively communicate the emergency to others in the airspace. Thus, setting the transponder to 7700 is the most effective means of signaling that an emergency is taking place.