Plant roots do not carry out photosynthesis so D.
Choice B:
More photosynthesis leads to more oxygen in the atmosphere and oceans.
Nice shift is the change in behavioral or feeding patterns by two or more competing populations to reduce interspecific competition. Interspecific competition is a type of competition between organisms of different species. A niche is a full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions.
