Three vertices of parallelogram $PQRS$ are $P(-3,-2), Q(1,-5), R(9,1)$ with $P$ and $R$ diagonally opposite. 
The sum of the coordinates of vertex $S$ is:
$\textbf{(A)}\ 13 \qquad \textbf{(B)}\ 12 \qquad \textbf{(C)}\ 11 \qquad \textbf{(D)}\ 10 \qquad \textbf{(E)}\ 9$
Graph the three points on the coordinate grid.  Noting that the opposite sides of a [parallelogram](https://artofproblemsolving.com/wiki/index.php/Parallelogram) are congruent and parallel, count boxes to find out that point $S$ is on $(5,4)$.  The sum of the x-coordinates and y-coordinates is $9$, so the answer is $\boxed{\textbf{(E)}}$.