To determine which expression equals 8, let's evaluate each option:
A. \((2^{\frac{1}{4}})^4\)
Using the power of a power property \((a^m)^n = a^{m \cdot n}\):
\[
(2^{\frac{1}{4}})^4 = 2^{\frac{1}{4} \cdot 4} = 2^1 = 2
\]
B. \((4^{\frac{1}{2}})^2\)
\[
(4^{\frac{1}{2}})^2 = 4^{\frac{1}{2} \cdot 2} = 4^1 = 4
\]
C. \((6^{\frac{1}{3}})^3\)
\[
(6^{\frac{1}{3}})^3 = 6^{\frac{1}{3} \cdot 3} = 6^1 = 6
\]
D. \((8^{\frac{1}{2}})^2\)
\[
(8^{\frac{1}{2}})^2 = 8^{\frac{1}{2} \cdot 2} = 8^1 = 8
\]
E. \((16^{\frac{1}{4}})^4\)
\[
(16^{\frac{1}{4}})^4 = 16^{\frac{1}{4} \cdot 4} = 16^1 = 16
\]
From the evaluations above, the expression that equals 8 is:
D. \((8^{\frac{1}{2}})^2\)