Answer: C. air high up in the atmosphere.
Cyclones outside the tropics are called as mid-latitude cyclones. In a typical cyclone wind moves in a circular fashion. As the surface wind rises it begins to rotate. The center of the cyclone origin site remains at low pressure. It results in less denser air to move upwards in the higher atmospheric layers. The movement of this air current is directionless. Therefore, middle-latitude cyclones are fueled by air currents air high up in the atmosphere.
