If she knows the function was a formal affair, she would not have worn jeans.

1. A Option A: If she knows the function was a formal affair, she would not have worn jeans.
2. B Option B: If she knew the function was a formal affair, she would not have worn jeans.
3. C Option C: If she had known the function was a formal affair, she would not have worn jeans.
4. D Option D: If she would know the function was a formal affair, she would not have worn jeans.

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