Final answer:
Technician B is correct; refrigerants in a vapor (gas) state can be compressed, while liquids are generally incompressible.
Step-by-step explanation:
When considering who is correct about the compressibility of refrigerants, Technician B's statement is accurate; refrigerant in a vapor (gas) state can be compressed. Gases are compressible because the molecules have enough space between them to be pushed closer together. This is a fundamental principle in the operation of refrigeration cycles where compressors are used to compress the refrigerant vapor, increasing its pressure before it is condensed back into a liquid form in the condenser. Technician A, however, is incorrect because liquids are generally considered incompressible due to their molecules being much closer together and having significantly less space to be compressed. Therefore, the correct answer to the question is option b, Technician B.