If $x=-4$ and $y=4$, which of the following expressions gives the largest answer?
(A) $\frac{x}{y}$
(B) $y-1$
(C) $x-1$
(D) $-x y$
(E) $x+y$
If $x=-4$ and $y=4$, then

$$
\begin{aligned}
& \frac{x}{y}=\frac{-4}{4}=-1 \\
& y-1=4-1=3 \\
& x-1=-4-1=-5 \\
& -x y=-(-4)(4)=16 \\
& x+y=-4+4=0
\end{aligned}
$$

Thus, $-x y$ is the largest.

Answer: (D)