拜托大家帮忙看一道GWD的逻辑题，我实在没明白

Q13:

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 from feeding on infected white-footed mice.  However, certain other species on which the larvae feed do not harbor the bacterium.  Therefore, if the population of these other species were increased, the number of ticks acquiring the bacterium―and hence the number of people contracting Lyme disease—would likely decline.

Which of the following, if true, most strengthens the argument?

1. Ticks do not suffer any adverse consequences from carrying the bacterium that causes Lyme disease in humans.
2. There are no known cases of a human’s contracting Lyme disease through contact with white-footed mice.
3. A deer tick feeds only once while in the larval stage.
4. A single host animal can be the source of bacteria for many tick larvae.
5. None of the other species on which deer tick larvae feed harbor other bacteria that ticks transmit to humans.

   Answer: C

上面是原题和答案，看起来感觉有点思路有点点乱，麻烦大家也帮我看一下。先谢谢了。

Which of the following, if true, most strengthens the argument?

1. Ticks do not suffer any adverse consequences from carrying the bacterium that causes Lyme disease in humans.
2. There are no known cases of a human’s contracting Lyme disease through contact with white-footed mice.
3. A deer tick feeds only once while in the larval stage.
4. A single host animal can be the source of bacteria for many tick larvae.
5. None of the other species on which deer tick larvae feed harbor other bacteria that ticks transmit to humans.

   Answer: C

上面是原题和答案，看起来感觉有点思路有点点乱，麻烦大家也帮我看一下。先谢谢了。

帖子怎么发成那样了？晕啊，大家光看上面部分就行了。

版主如果可以，帮我改一下，或者告诉我怎么改？我改过但没改过来。谢谢