请教大全12及debate用法

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！

Same question, still no answer!

UP UP!

[intransitive and transitive]
1
to discuss a subject formally when you are trying to make a decision or find a solution
The issue will be debated on Tuesday.
debate whether/what/how etc
Meanwhile, philosophers debate whether it's right to clone an individual.
debate (something) with somebody
an invitation to debate with William on the future of democracy
His conclusions are hotly debated (=argued about strongly) .
2
to consider something carefully before making a decision
debate with yourself
I debated with myself whether I should tell anyone.
debate who/what/how etc
I'm still debating what to do.
debate doing something
For a moment Mary debated telling Rick the truth.

建议jj下载牛津词典，在下载区有的。

很崇拜JJ的阅读的说^_^