【单选题】Bracken,一种有毒的野草,正在北半球蔓延并毁坏了许多牧场。一种潜在的费用低廉而且可以自我维持的对付办法是引入这种植物的天敌;因此,一些科学家建议通过把产于南半球的吃bracken的飞蛾放养到受bracken影响的北半球地区来控制bracken的生长。如果科学家控制bracken的建议被采纳,下面哪个是其成功所必要的条件?
A.
南北半球的bracken生长的地区必须拥有相同的气候和土壤条件。
B.
释放的飞蛾以野草为食,但不吃原产于北半球的bracken。
C.
回到现在遍地都是bracken的牧场的家畜要对bracken引起的疾病有免疫力。
D.
放养的飞蛾存活数量形成的群体足够减少bracken并抑制它的生长。
E.
一些传统的控制办法如火烧、刀割、喷化学药品等并不比现在的方法少花钱、少用劳动力。
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