Wind energy is
Free of cost and pollution-free
Explanation of the Correct Options
Explanation of the incorrect options
Option(A):
Wind energy is renewable energy but not exhaustible.
Option(B):
Wind is not nonrenewable energy and is not exhaustible.
Option(D):
Wind energy is pollution-free but not costly.
Thus, wind energy is free of cost and pollution-free.
Hence, option C is the correct answer.