Sentence Correction (SC) | Re: Since 1998, when the first direct discovery of so-called dark energy

Option (D)

I took 50 seconds.

As Zhanbo correctly pointed out the need to have present perfect tense because of the presence of "Since", I eliminated (A), (B) & (C) based on that.

(E) did not make sense because of the use of "that".

So, (D) is the correct answer

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