1997 AHSME Problem 6

Consider the sequence

1,-2,3,-4,5,-6,\ldots,

whose nth term is (-1)^{n+1}\cdot n. What is the average of the first 200 terms of the sequence?

\textbf{(A)}-\!1\qquad\textbf{(B)}-\!0.5\qquad\textbf{(C)}\ 0\qquad\textbf{(D)}\ 0.5\qquad\textbf{(E)}\ 1

Full credit goes to MAA for authoring these problems. These problems were taken on the AOPS website.