Answer:
B
Step-by-step explanation:
[tex]\sqrt[4]{9} ^{\frac{1}{2} x} =((9)^{\frac{1}{4} } )^{\frac{1}{2} x} \\=(9)^{(\frac{1}{4} \times \frac{1}{2} x)} \\=9^{\frac{1}{8} x}[/tex]
