请教GWD-9-Q23

After more than four decades of research and development, a new type of jet engine is being tested that could eventually propel aircraft anywhere in the world within two hours or help boost cargoes into space at significantly lower costs than current methods permit.

A.         tested that could eventually propel aircraft anywhere in the world within two hours or help

B.         tested that could eventually have the capability of propelling aircraft anywhere in the world within two hours or to help

C.         tested, eventually able to propel aircraft anywhere in the world within two hours, or helping

D.        tested, and it eventually could propel aircraft anywhere in the world within two hours or helping

      E.    tested, and it could eventually have the capability to propel aircraft anywhere in the world within two hours or help

多谢大虾指点……

好厉害啊，是A没错，可是我不知道 tested that could 都做什么成分啊，总觉得别扭……

感谢牛牛的回答~

路过帮顶，这个 that 在这里是什么意思呢？

定语从句吗，如果修饰a new type of jet engine 是不是远了点哦

同意~

E for me. and also I think gwd gives the answer of e in his gmat training class.

A sounds like that the "engine testing" could eventually propel aircraft.....