If a refrigeration compressor using a thermostat as a primary controller is running continuously without significantly lowering the temperature in the refrigerated space, which of the following is most likely the trouble?

Correct Answer: Option C — a shortage of refrigerant

A low refrigerant charge strips the system of necessary latent heat capacity, preventing the evaporator from absorbing sufficient heat. Consequently, the compressor runs continuously without making headway against the ambient heat load entering the space.