Answer:
B. 8
Explanation:
[tex]64=8\times8[/tex]We can write this in index form as:
[tex]64=8^2[/tex]Therefore:
[tex]\sqrt[]{64}=\sqrt[]{8^2}[/tex]On the right-hand side, the square root sign cancels the square, so we have:
[tex]\sqrt[]{64}=8[/tex]The correct choice is B.