Which of the processes listed would be the most satisfactory method to use to lower the humidity of the air being circulated by an air conditioning system?（）
- ACooling the air to a temperature just above dew point
- BHeating the air to a point at which moisture will boil off ,then re-cooling it
- CCooling the air to a point below dew point, then reheating it
- DHeating the air and then cooling it to a point below dew point