大全12、

A little under a million years ago, the briny waters of the Baltic Sea began flooding into the cold North Atlantic: geologists are still debating whether the flood was gradual or created a cataclysm.

(A) whether the flood was gradual or created a cataclysm

(B) if the flood was gradual or created a cataclysm

(C) about whether the flood was gradual or cataclysmic

(D) whether the flood was gradual or cataclysmic（D）

(E) whether the flood was gradual or it created a cataclysm

C和D的唯一的区别在于C多了一个debate，但是我今天查了牛津双解词典（手上暂无其他词典），用法说debate (about) sth，并举了几个例子 what are they debating (about)? / we're just debating what to do next./ they debated closing the factory.

我想请问的是：此题是因为简洁的需要才选D的，还是说debate about的用法是错误的呢？有没有大牛能帮我看看debate的用法呢？谢谢！

我见过：debate on(upon) ;但是没见过debate about