How do consumers get the carbon that we need?

Breathing it in.

Because, when humans breath they consume carbon.

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.

frogs. the lower the ph the higher the acid content. frogs have the highest tolerance in this scenario.