I ______ if she was there.
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would have known
-
knew
-
know
-
had known
A
Correct answer
Explanation
This sentence expresses a hypothetical past situation using the third conditional structure. "Would have known" is the correct form because it refers to an unrealized possibility in the past - you didn't actually know because she wasn't there. "Knew" and "know" are for real situations, while "had known" would require a different sentence structure.