Final Answer:
The refrigerant that causes the least amount of damage to the ozone layer among the options provided is d) HFO-1234yf.
Step-by-step explanation:
HFO-1234yf is a hydrofluoroolefin (HFO) which has an ozone depletion potential (ODP) of zero. ODP measures the relative destructive ability of a substance towards the ozone layer compared to CFC-11, which has an ODP of 1.0. Both CFC-12 and HCFC-22 have significant ODP values, contributing to ozone layer depletion, while HFC-134a, although having a low global warming potential (GWP), still possesses a non-zero ODP.
CFC-12, also known as R-12, has an ODP of 1.0, indicating its high ozone-depleting potential. HCFC-22, also known as R-22, though less harmful than CFCs, still possesses an ODP of 0.055, making it detrimental to the ozone layer. HFC-134a, commonly used as a refrigerant, has an ODP of 0, which is better than CFCs and HCFCs, but it still contributes to global warming due to its high GWP.
However, HFO-1234yf stands out as an environmentally friendly option. With an ODP of zero, it doesn't contribute to ozone depletion, and it has a low GWP, making it a more sustainable choice for refrigeration systems, significantly reducing their environmental impact compared to the other listed refrigerants.