Which of the following changes between trophic levels would have the highest energy conversion efficiency? a) producer to primary consumer b) primary consumer to secondary consumer c) secondary consumer to tertiary consumer d) none of the above

Im pretty sure its B

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.