This graph gives information on greenhouse gas (GHG) emissions from generating electricity in the United States. Which questions would help clarify this evidence?

Can nonrenewable resources be used sustainably?   a. yes, nonrenewable resources are always beneficial for the environment  b. no, there are only negative effects of using nonrenewable resources  c. no, there's a finite amount of nonrenewable resources  d. yes, as long as use doesn't exceed availability is the correct answer   d. yes, as long as use doesn't exceed availability