If the superheat setting of a thermostatic expansion valve is set too low, what would be the result, assuming that the system has a single evaporator?

Correct Answer: Option D — the suction line will be abnormally cold and liquid may flood back to the compressor

Setting the thermostatic expansion valve superheat too low causes the valve to remain excessively open, flooding the evaporator with liquid refrigerant. The liquid fails to completely boil off, resulting in an abnormally cold suction line and potential liquid slugging into the compressor cylinders.