Significant. Fractional sounds like "fraction," which is typically meaning a value less than one, but not quite zero. AKA, very small.
The opposite of a very small change would be a very big change. Which is what a significant change is.
Answer:
The sentence is correct as written.
Explanation:
You didn't include the original sentence but, all of the answer choices are incorrect.
I think it’s B I remember taking a test with this question