Read this passage from Alan Weisman's "The City Without Us":
Plants from the Americas changed not only ecosystems in European countries but also their very identities: think of Ireland before potatoes, or Italy before tomatoes. In the opposite direction, Old World invaders [introduced] seed, beginning with wheat, barley, and rye. In a phrase coined by the American geographer Alfred Crosby, this ecological imperialism helped European conquerors to permanently stamp their image on their colonies.Now read this passage from Jared Diamond's "The Ends of the World as We Know Them":A major factor [in the collapse of Maya society] was environmental degradation by people: deforestation, soil erosion and water management problems, all of which resulted in less food. Those problems were exacerbated by droughts, which may have been partly caused by humans themselves through deforestation.

What common theme of green literature is most strongly evident in both passages?

A.The actions of human beings can have a strong destructive impact on the natural environment.
B.Nature is such a strong force that it continues to pose challenges even to modern societies.
C.There is no excuse for damaging the natural world, and anyone who does so will pay a steep price.
D.With careful management, ecosystems can still thrive after human beings have changed them.