Q19 The fact of some fraternal twins resembling each other greatly and others looking quite dissimilar highlights an interesting and often overlooked feature of fraternal-twin pairs, namely they vary considerably on a spectrum of genetic relatedness.

A)

B) That some fraternal twins resemble each other greatly while others look quite dissimilar highlights an interesting and often overlooked feature of fraternal-twin pairs, namely that they vary considerably

c) With some fraternal twins resembling each other greatly and others looking quite disimilar, it highlights an interesting and often overlooked feature of fraternal-twin pairs, namely considerable variation

d) With some fraternal twins resembling each other greatly and others looking quite disimilar, it is a fact that highlights an interesting and often overlooked feature of fraternal-twin pairs, namely a considerable variation

E) Because some fraternal twins resemble each other greatly and others look quite disimilar, this fact highlights an interesting and often overlooked feature of fraternal-twin pairs, namely they vary considerably

Answer is B

i know A is not right because it should be "the fact that..."

"With .." on C doesnt modify "it" correctly..

and i am stuck with B, D, and E...

Also, i am quite confused with "namely that they vary considerably"

~thanks in advance~

这句话到底在讲些什么啊？因为实在选不出，胡乱选了C，我看B怎么看都不像句子呀，有谁能帮帮我们？