The author discusses "the cactus-feeding moth" in Florida in order to A. explain why the prickly pear species that are native to Florida have no indigenous predators B. show how a predator spreads more rapidly in alien environments than it does in its native environment C. indicate that a single nonindigenous predator species can be effective against a wide array of nonindigenous pest species D. argue that controlling pests with nonindigenous predators can have unintended consequences