How Do Scientists Suggest We Solve the "Trilemma" Created by the Shift

How do scientists suggest we solve the "trilemma" created by the shift in recent years from fossil fuels to biofuels, such as ethanol?

A) They suggest we eat less food
B) They suggest that governments offer additional subsidies for farmers who are growing biofuel crops
C) They suggest that biofuel production should be carried out in very particular ways, such as by growing perennial grasses on abandoned fields
D) They suggest that we ride our bikes and walk rather than drive