Final answer:
HFC-134a is the refrigerant with the lowest ODP rating of 0.
Step-by-step explanation:
The refrigerants HFC-134a and HCFC-141b have been identified as promising replacements for older refrigerants, such as carbon tetrachloride (CC). HFC-134a, also known as CF3-CH₂F, has an ozone depletion potential (ODP) rating of 0, making it one of the refrigerants with the lowest ODP rating. This means that it has minimal impact on the ozone layer. On the other hand, HCFC-141b, also known as CH₂-CC1₂F, has a slightly higher ODP rating of 0.11. Therefore, HFC-134a is the refrigerant with the lowest ODP rating.