Answer:
The correct option is;
C. Low refrigerant charge
Step-by-step explanation:
Where both the low-side and the high-side pressure are low the refrigerant is low which may be as a result of a leak
When there is a low refrigerant charge there will be a larger range over which to compress the refrigerant increasing the work required and thus the heat in the system and the due to insufficient refrigerant, the entire system is under served and the evaporator super-heats due to lack of refrigerant
The liquid-line, the TVX evaporator and compressor will see less fluid flow and hence lesser pressures on the low-side and high-side of the refrigeration system.