Q. Consider the following:
1.Aerosols
2.Foam agents
3.Fire retardants
4.Lubricants
In the making of how many of the above are hydrofluorocarbons used?
Answer: C
Notes:
Exp) Option c is the correct answer.
Option 1, 2, 3 are correct: HFCs are entirely man-made. They are primarily produced for use in refrigeration, air-conditioning, insulating foams and aerosol propellants, with minor uses as solvents and for fire protection.
Option 4 is incorrect: Although HFCs are entirely produced for use in refrigeration, insulating foams and aerosol propellants and air-conditioning, with minor uses as flame retardents but they are not used for making lubricants.

