What is the primary refrigerant used in a medium-temperature commercial refrigeration system?

Exam tip

Remember the different applications of refrigerants based on their temperature ranges and environmental impact.

Why C is correct

R-404A is commonly used in medium-temperature commercial refrigeration systems due to its high refrigeration capacity and low environmental impact compared to ammonia. Ammonia is used in low-temperature systems due to its high toxicity and flammability. R-134a and R-410A are more suitable for residential and light commercial air conditioning systems.