The value of ( 256 )^5/4 is = ?

Answer: Option C

$$\begin{array}{rl}& {\left(256\right)}^{\frac{5}{4}}\\ & ={\left(4^4\right)}^{\frac{5}{4}}\\ & =4^{\left(4\times \frac{5}{4}\right)}\\ & =4^5\\ & =1024\end{array}$$