What is net energy yield and why is it important in evaluating energy resources?

total amount of useful high energy available from a resource MINUS energy needed to make energy available to consumers.

Explanation:

it is important for evaluating energy resources because any energy resource with a low or negative net energy yield cannot compete in open markets with alternatives that have high net energy yields.

i would imagine your answer to be b.

i'm not could be wrong.

(also for future reference, their is an 'arts' category. : )