The main advantage of solar energy is: a. it is low in cost. b. it can be used all the time. c. it has very little pollution. d. it is free.

C.  Solar energy's whole purpose it to reduce pollution in the air that fossil feuls do not. The answer cannot be A. B. or D. because 1. it is expensive 2. it can only be used during the daytime. It is a SOLAR panel. and 3. like is said earlier it is not free.

C it has very little pollution

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