Several Chemical Pollutants from a Paper Mill Are Released into the Nearby

Several chemical pollutants from a paper mill are released into the nearby environment. Compound A is rich in calcium and magnesium. Compound B binds tightly to all free polypeptides and proteins in the soil. Compound C is structurally similar to abscisic acid. Based on this scenario, which compound will most likely harm the surrounding vegetation, and what effect(s) will it have on the plants?

A) Compound A; because these minerals will act as toxins to the plant as they are absorbed through the roots.
B) Compound B; because the uptake of polypeptides and proteins from the soil is critical for plant growth.
C) Compound C; because abscisic acid inhibits the active transport of potassium ions and thus closes the stomata. It will interfere with both carbon dioxide uptake and water transport.