GWD 24-23 还是看不懂

24-23 Discussion of greenhouse effects has usually focused on whether the Earth would warm and by how much, but climatologists have indicated all along that the most obvious effects, and those that would have the largest impact on people, would be extremes of temperature, precipitation, and storminess.

A) the most obvious effects, and those that would have the largest impact on people, would be extremes of temperature, precipitation, and storminess.

B) the effects that are the most obvious ones, extremes of temperature, precipitation, and storminess, would be those impacting the most on people.

C) those effects to have the largest impact on people, extremes of temperature, precipitation, and storminess, are what are the most obvious effects.

D) extremes of temperature, precipitation, and storminess, the most obvious

effects, that they would have the largest impact on people.

E) extremes of temperature, precipitation, and storminess, which are the most obvious effects, are those to impact the most on people

请大家帮忙，马上要考了，可是还有好多不懂的，这一个题，答案是D.没看出来这个题目的考点，汗。。。。B,E哪里错呢。D中的 ， that they would have the largest impact on people, that 怎么引导起非限制性定于从句来呢了？

谢谢