[大后天考]请教大全281题，在PP3上遇到了。

dxwei2008

281. Even their most ardent champions concede that no less than a technical or scientific breakthrough is necessary before solar cells can meet the goal of providing one percent of the nation’s energy needs.

(A) that no less than a technical or scientific breakthrough is necessary
(B) that nothing other than a technical or scientific breakthrough is needed
(C) that a technical or scientific breakthrough is necessary
(D) the necessity for an occurrence of a technical or scientific breakthrough
(E) the necessity for a technical or scientific breakthrough occurring

请教大全281题，答案选C。
请高手详细讲解一下，为什么其他答案都不行啊？看上去好象没什么不好死的。我选的是B。

turtlechen

Please check OG-242!