GMAT Critical Reasoning (CR) | Re: Ethanol, a fuel derived from corn, can be used alone to power cars

The main idea is tosave energy and reduce pollution .And we need to evaluate if the increased usage of ethanol as a primary fuel source in conjunction with or in place of gasoline.

(A) Whether the energy required to grow and process the corn used as fuel is greater than the amount of energy ultimately produced.
Incorrect.The idea is to save energy.So, We need to evaluate the energy IN and energy out. (B) Whether more energy is saved when using ethanol in conjunction with or in place of gasoline.
Correct.This
...

---