求助Prep-100

100.  Lyme disease is caused by a bacterium transmitted to humans by deer ticks.  Generally, deer ticks pick up the bacterium while in the larval stage by feeding on infected white-footed mice.  However, certain other species on which the larvae feed do not harbor the bacterium.  If the population of these other species were increased, more of the larvae would be feeding on uninfected hosts, so the number of ticks acquiring the bacterium would likely decline.

Which of the following would it be most important to ascertain in evaluating the argument?

(A)  Whether populations of the other species on which deer tick larvae feed are found only in areas also inhabited by white-footed mice

(B)   Whether the size of the deer tick population is currently limited by the availability of animals for the tick's larval stage to feed on

(C)   Whether the infected deer tick population could be controlled by increasing the number of animals that prey on white-footed mice

(D)  Whether deer ticks that were not infected as larvae can become infected as adults by feeding on deer on which infected deer ticks have fed

(E)   Whether the other species on which deer tick larvae feed harbor any other bacteria that ticks transmit to humans

正确答案是B 看了很多人的解释实在不能理解为甚么。

我的想法是这样的： B中说tick 的数量被限制了 也就是说tick 的数量不会增长。 如果其他的可以被tick 吃的物种增加了， tick 依旧可以吃他们啊 不管tick有没有被限制 只要其他物种的数量增多了 tick 吃白脚鼠的可能性就降低了，那么被感染的概率就低了啊 感觉B是个无关选项啊。

求助~~ 多谢了