Ans: A
$\begin{array}{cl}
& 5^{334}\left(\dfrac{-1}{5}\right)^{333} \\
= & – 5^{334}\div 5^{333} \\
= & -5^{334-333} \\
= & -5
\end{array}$
$\begin{array}{cl}
& 5^{334}\left(\dfrac{-1}{5}\right)^{333} \\
= & – 5^{334}\div 5^{333} \\
= & -5^{334-333} \\
= & -5
\end{array}$
