we have
[tex](\sqrt[4]{9}) ^{\frac{1}{2}x}[/tex]
we know that
[tex](\sqrt[4]{9}) ^{\frac{1}{2}x}=(9^{\frac{1}{4}})^{\frac{1}{2}x}\\ \\=9( ^{\frac{1}{4}*\frac{1}{2}x}) \\ \\=9( ^{\frac{1}{8}x})[/tex]
therefore
the answer is the option B
[tex]9(^{\frac{1}{8}x})[/tex]
