jmc

We know where points $A$, $B$, and $C$ are, and we know that the shape is a parallelogram, so we know that the differences in the x-values and y-values between $B$ and $A$ must be the same as the differences in x-values and y-values between $C$ and $D$.

The solution is $\boxed{(-5,-4)}$, which keeps the vertices in alphabetical order, as shown in the first figure. Two other parallelograms are shown in figures 2 and 3 (where we number them from left to right), but they are not solutions because the points aren't in the correct order. They would be parallelograms $ACBD$ and $ABDC$, respectively.