Sentence Correction

Princess Diana's dresses set the standard for all fashion houses in Europe. Such a thing didn't happen before or since.
didn't happen before or
had neither happened before or
hadn't happened before and hasn't happened
didn't happen before and hasn't happened
hasn't happened either before or

I think its B

It is wordy but Is it C?

OA is C

B is surely to be eliminated as "neither" and "or" - wrong idiom

Can anyone provide explanation for others?

This is similar to the one you posted earlier.

https://www.beatthegmat.com/report-t101692.html#441920

Same error here, both the sentence parts Such a thing didn't happen before or since should have the verb or not at all to be parallel Hope you get that.

A B E - wrong because of the above reason
B - neither or - wrong, we need neither nor

Between C and D, its a tense issue.
use of hadn't refer to the period before (past perfect) and hasn't from then till now (simple past).
D - wrong tense, both uses simple past.

Was mixed between C and D, but found the reason in D once i saw the OA. Nice question by the way.

IMO C. Hope this helped