Which of the following most logically completes the passage?

Each species of moth has an optimal body temperature for effective flight, and when air temperatures fall much below that temperature, the moths typically have to remain inactive on vegetation for extended periods, leaving them highly vulnerable to predators. In general, larger moths can fly faster than smaller ones and hence have a better chance of evading flying predators, but they also have higher optimal body temperatures, which explains why ______.

1. large moths are generally able to maneuver better in flight than smaller moths
2. large moths are proportionally much more common in warm climates than in cool climates
3. small moths are more likely than large moths to be effectively camouflaged while on vegetation
4. large moths typically have wings that are larger in proportion to their body size than smaller moths do
5. most predators of moths prey not only on several different species of moth but also on various species of other insects

答案选择B，可我怎么也看不出来是B，我觉得像是C，请大虾指教，3X~!

补充：关于C。其实八竿子大不着。就算对，那你小家伙能藏，我大蛾子岂不是不搞死，反倒成小家伙成活率高了，推出与原文相反结果。你觉得呢。

我不是大虾，我是菜鸟，但是逻辑有点心得。我后天考试，希望能帮到仍然苦恼逻辑的XDJM。

原文说，每个蛾的飞行都要保持一定的温度。当温度降低，蛾们就要躲起来停留一段时间来保持一定温度不要降低。但是这样又极易受到攻击。因为大蛾飞的比较快，所以不容易被扑捉。可是他们又需要更高的温度来维持飞行，（所以...），这就可以解释为什么

其实，这里就是问的（所以...)相关的内容。

想想，（所以...)应该是哪方面的内容----大蛾需要停留在暖和的地方更长的时间。

答案中只有B与上边最符合。