The correct answer is C) remove some refrigerant from the system. When a refrigeration compressor has a high head pressure due to an overcharge of refrigerant, the best way to correct this is to remove some of the excess refrigerant from the system. An overcharge of refrigerant causes the condenser to become overcrowded, resulting in higher head pressures and reduced efficiency. Removing some of the refrigerant will allow the system to operate at the proper pressures and temperatures. The other options are incorrect because: A) increasing cooling water would not address the root cause of the high head pressure, which is the refrigerant overcharge; B) decreasing cooling water would further exacerbate the high head pressure issue; and D) raising the high-pressure cut-out pressure would only mask the problem without fixing it.