Consider the property of exponents,
[tex](x^m)^n=x^{m\cdot n}[/tex]
The expression is given as,
[tex](\sqrt[]{s})^2[/tex]
The square root operation is nothing but an exponent 1/2.
[tex]\sqrt[]{x}=x^{\frac{1}{2}}[/tex]
Then the given expression can be resolved as,
[tex](\sqrt[]{s})^2=(s^{\frac{1}{2}})^2=(s)^{\frac{1}{2}\cdot2}=s^1=s^{}[/tex]
Thus, the given expression can be written as,
[tex](\sqrt[]{s})^2=s[/tex]
Therefore, option C is the correct choice.
