Why might a car's air conditioning system blow cold air when idle but warm air when moving?
A. The air conditioning system is not functioning properly and needs maintenance.
B. The engine's cooling system is not efficiently cooling the AC refrigerant when the car is in motion.
C. The air conditioning system's fan is malfunctioning and only works at high speeds.
D. The car's air conditioning system is designed to blow cold air only when the car is moving.