To simplify \(\sqrt{252}\), we first factor \(252\):
\[ 252 = 2^2 \times 3^2 \times 7 \]
Now we can take the square root:
\[ \sqrt{252} = \sqrt{2^2 \times 3^2 \times 7} = \sqrt{(2 \times 3)^2 \times 7} = 6\sqrt{7} \]
Thus, the simplified form is \(6\sqrt{7}\).
Considering the given options, the correct response is:
6 square root of 7.