Which is equivalent to [tex]\sqrt[4]{9} ^{\frac{1}{2}x }[/tex]

A: [tex]9^{2x}[/tex]
B:[tex]9^{\frac{1}{8}x }[/tex]
C:[tex]\sqrt{9}^{x}[/tex]
D:[tex]\sqrt[6]{9} ^{x}[/tex]



ANSWER IS B: :[tex]9^{\frac{1}{8}x }[/tex]