Afluid that vaporizes and condenses inside the tubing of a heat pump is called the.
a. compressor.
b. fuel.
c. refrigerant.
d. condenser.

option C. Refrigerant. When the fluid vaporizes(passes from liquid to vapor) absorbs a lot of energy (called latent vaporization heat) which causes that the surroindings cool. The latent vaporization heat of the fluid permits the refrigeration process and the fluid is the refrigerant, this is the substance that permit that the refrigeration process take place.