B. Formal operational stage of cognitive development
A keystone species helps define an entire ecosystem. Without its keystone species, the ecosystem would be dramatically different or cease to exist altogether.
Embryology, the study of the development of the anatomy of an organism to its adult form, provides evidence for evolution as embryo formation in widely-divergent groups of organisms tends to be conserved. ... Another form of evidence of evolution is the convergence of form in organisms that share similar environments.
I would say its A because it is doing something harmful
