请教各位大神，关于spacecraft的单复数问题 >_<

Unlike the short flights of the shuttle andearlier spacecraft, which carried sufficient power in fuel cells and batteries,a permanently orbiting space station will have to generate its own electricity.

A.    the short flights of the shuttle and earlier spacecraft, which carriedsufficient power in fuel cells and batteries,

B.    the shuttle and earlier spacecraft, with sufficient enough power in fuelcells and batteries for their short flights,

C.    the short flights of the shuttle and earlier spacecraft, which enabledthem to carry sufficient enough power in fuel cells and batteries,

D.     the shuttle and earlier spacecraft, which werecapable of carrying sufficient power in fuel cells and batteries for theirshort flights,           (D)

E.    the flights of the shuttle and earlier spacecraft, whose shortnessallowed them to carry sufficient power in fuel cells and batteries,

（5）集体名词如
agency/army/audience/class/committee/crowd/orchestra/team/baggage/citrus/ equipment/fleet/fruit/furniture等，在GMAT考试中几乎都认为是单数的主语。

所以就一下子迷茫在人生的十字路口了 >_<   在CD以及其他网站上没有找到想要的答案所以还是发个帖问问，万一有重复的帖了，辣我就不好意思了米娜桑！

求大神解惑，谢谢啦~