In an area with plants that have thick, small leaves or no true leaves at all, which of the following conditions is most likely to exist as well?

a

explanation:

an active site is a region that is present on an enzyme where the reactants or the substrate molecules we can say bind and experience a chemical reaction. the substrate is basically a reactant whose concentration is changing and that is converting into a product after binding at the active site of an enzyme

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.

option c is the correct answer.