prep一题请教斑竹-弱问

28(网上讨论)

In some species of cricket, the number of chirps per minute used by the male for attracting females rise and fall in accordance with the surrounding temperature, and they can in fact serve as an approximate thermometer.

a.       for attracting females rise and fall in accordance with the surrounding temperature, and they can in fact serve

b.      for attracting females rise and fall in accordance with the surrounding temperature, which can in fact serve

c.       in attracting females rise and fall in accordance with the surrounding temperature, in fact possibly serving

d.      to attract females rises and falls in accordance with the surrounding temperature, and it can in fact serve

e.       to attract females rises and falls in accordance with the surrounding temperature, in fact possibly serving

answer (d) 为何and之前有逗号？