which of the following is a scenario that describes how microbes could positively impact the environment and/or human activities? choose all that apply and only those that apply. a. microbes can be added to the roots of legumes to fix atmospheric nitrogen, thus increasing the fertility of the plants and surrounding soil b. microbes play roles in the biogeochemical processes that recycle molecules such as those containing nitrogen, phosphorus, and carbon in the environment c. microbes could be used to remove the overgrowth of submerged aquatic vegetation in the northern gulf of mexico following nutrient input d. microbes such as lactococcus spp. can be used to supplement human diets, thus aiding in digestion