Hey!
Lets take the square root of all these answer choices.
√63 ≈ 7.9
√99 ≈ 9.4
√83 ≈ 9.1
√10 ≈ 3.2
So if we look at all the answer choices square root, the answer that is the closest to 9 is √83.
Therefore, your answer will be C. square root of 83.
Hope this helps! :)
