#### Answer

$\text{G}$

#### Work Step by Step

Recall:
$(a-b)^2=a^2-2ab+b^2$
Use the formula above to obtain:
\begin{align*}
(8-5i^2)^2&=8^2-2(8)5i)+(5i)^2\\
&=64-80i+25i^2\\
\end{align*}
With $i^2=-1$< then the equation above becomes:
\begin{align*}
(8-5i)^2&=64-80i+25(-1)\\
&=64-80i-25\\
&=39-80i
\end{align*}