Which of the following statement is wrong?

A. The performance of the vapour compression refrigerator varies considerably with both vaporising and condensing temperatures.

B. In vapour compression cycle, the useful part of the heat transfer is at the condenser.

C. In ammonia-hydrogen (Electrolux) refrigerator, no compressor, pump or fan is required.

D. The effect of under-cooling the liquid refrigerant is to decrease the coefficient of performance.

Please do not use chat terms. Example: avoid using "grt" instead of "great".