Some microorganisms reside in soil and on plant roots and undergo a process called nitrogen fixation which turns nitrogen from the atmosphere into compounds that are absorbed by plants. What best describes the role of the microorganisms? A The microorganisms disrupt the health of organisms in the ecosystem. B The microorganisms aid in the processes of decomposition. C The microorganisms aid in the cycling of nutrients in the ecosystem. The microorganisms cause disease in plants and animals.