As given by the question
There are given that the expression
[tex]\sqrt[]{45}[/tex]Now,
The value of the given expression is:
[tex]\begin{gathered} \sqrt[]{45}=\sqrt[]{5\times9} \\ =\sqrt[]{9}\times\sqrt[]{5} \\ =3\sqrt[]{5} \end{gathered}[/tex]Hence, the correct option is C.