Answer: The jet plane's speed of 200 m/s is relative to the ground. This means that the jet plane is moving at a speed of 200 m/s relative to the ground below it.
Explanation: The speed of an object can be relative to anything, but it is usually specified relative to a stationary object, such as the ground. In this case, the ground is a stationary object, so the jet plane's speed is relative to the ground.
If the jet plane were to fly over a moving object, such as a car, then the jet plane's speed would be relative to the car. However, in this case, the jet plane is flying over a stationary object, so the jet plane's speed is relative to the ground.