Question ID:PT54 S4 Q11 Passage:Australia has considerably fewer species of carnivorous mammals than any other continent does but about as many carnivorous reptile species as other continents do. This is probably a consequence of the unusual sparseness of Australia's ecosystems. To survive, carnivorous mammals must eat much more than carnivorous reptiles need to; thus carnivorous mammals are at a disadvantage in ecosystems in which there is relatively little food. Stem:Which one of the following most accurately expresses the main conclusion of the argument? Correct Answer Choice:CChoice A:Australia has considerably fewer species of carnivorous mammals than any other continent does but about as many carnivorous reptile species as other continents do. Choice B:In ecosystems in which there is relatively little food carnivorous mammals are at a disadvantage relative to carnivorous reptiles. Choice C:The unusual sparseness of Australia's ecosystems is probably the reason Australia has considerably fewer carnivorous mammal species than other continents do but about as many carnivorous reptile species. Choice D:The reason that carnivorous mammals are at a disadvantage in ecosystems in which there is relatively little food is that they must eat much more in order to survive than carnivorous reptiles need to. Choice E:Because Australia's ecosystems are unusually sparse, carnivorous mammals there are at a disadvantage relative to carnivorous reptiles.