大全sec2-1,没讨论过

A fire in an enclosed space burns with the aid of reflected radiation that preheats the fuel, making ignition much easier and flames spreading more quickly.

(A) flames spreading

(B) flame spreads

(C) flames are caused to spread

(D) causing flames to spread（D）

(E) causing spreading of the flames

不明白e为什么不对，我觉得e很是对称啊，spreading前文的ignition,都是动作性名词，而d的对称性反而不如e，解释看了还是不明白

spread本身就可以作名词，这里如果用spreading是不是有点画蛇添足了呀？