If $8\cdot2^x = 5^{y + 8}$, then when $y = - 8,x =$
$\textbf{(A)}\ - 4 \qquad\textbf{(B)}\ - 3 \qquad\textbf{(C)}\ 0 \qquad\textbf{(D)}\ 4 \qquad\textbf{(E)}\ 8$
Simple substitution yields
\[8 \cdot 2^{x} = 5^{0}\]
Reducing the equation gives
\[8 \cdot 2^{x} = 1\]
Dividing by 8 gives
\[2^{x}=\frac{1}{8}\]
This simply gives that $x=-3$.
Therefore, the answer is $\fbox{(B) -3}$.