GWD1-Q28,我还是搞不懂啊?

          interested in a tide-associated

         periodic behavior displayed by

Line      the diatom Hantzschia virgata, a

  (5)     microscopic golden-brown alga that

inhabits that portion of a shoreline

washed by tides (the intertidal zone).

Diatoms of this species, sometimes

called “commuter” diatoms, remain

 (10)     burrowed in the sand during high

tide, and emerge on the sand sur-

face during the daytime low tide.

Just before the sand is inundated by

the rising tide, the diatoms burrow

 (15)     again.  Some scientists hypothesize

that commuter diatoms know that it

is low tide because they sense an

environmental change, such as an

alteration in temperature or a change

 (20)     in pressure caused by tidal move-

         ment.  However, ....

GWD1-Q28:

The primary purpose of the passage is to

1. dispute the influence of environmental factors on the tide-associated behavioral rhythms displayed by the diatom Hantzschia virgata

2. describe how certain tide-associated behavioral rhythms displayed by the diatom Hantzschia virgata have changed over time

3. compare tide-associated behavioral rhythms to solar-day behavioral rhythms in the diatom Hantzschia virgata

4. examine how certain biological and environmental influences affect the tide-associated behavioral rhythms displayed by the diatom Hantzschia virgata

5. identify certain environmental factors that limit the effectiveness of the biological clock in the diatom Hantzschia virgata

看过讨论, 觉得D虽然讲了文章的意思,但是问题问的是the primary purpose,不是main idea?我摘录下来的内容都是作者阐述的其他科学家的观点,从however后面开始批判.所以,我觉得主要的意图就应该选A啊?

这题我也是没有搞明白A为什么不行，有的说文中不仅有反对也有赞成，可是dispute不是也有议论讨论的意思么？D选项的examine好像有点奇怪啊

dispute是争论性的讨论不一样的