Select the correct answer. The pie chart shows that electricity production emits the most greenhouse gases in the United States. According to the Environmental Protection Agency (EPA), about 67% of this electricity is produced by burning fossil fuels, while more than 90% of the fuel used for transportation comes from fossil fuels. What changes must humans make to protect the environment from the greenhouse gas emissions produced by fossil fuels?

A.
Reduce the percentage of renewable energy sources.
B.
Increase the amount of greenhouse gasses produced by agriculture.
C.
Promote the use of private transportation.
D.
Invest in clean, cost-effective energy.