In a refrigeration system featuring low-side pump down prior to the automatic shut down of the compressor, the temperature of the refrigerated space is controlled by the action of a thermostat wired to what device?

Correct Answer: Option D — liquid line box solenoid

A low-side pump-down system uses a box thermostat wired to the liquid line solenoid. When the desired space temperature is reached, the solenoid closes, isolating the liquid feed and allowing the compressor to pump the low side down before tripping on the low-pressure switch.