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?

A．Cooling the air to a temperature just above dew point

B．Heating the air to a point at which moisture will boil off ,then re-cooling it

C．Cooling the air to a point below dew point, then reheating it

D．Heating the air and then cooling it to a point below dew point