1992 AHSME Problem 12

Let y=mx+b be the image when the line x-3y+11=0 is reflected across the x-axis. The value of m+b is

\text{(A) -6} \quad \text{(B) } -5\quad \text{(C) } -4\quad \text{(D) } -3\quad \text{(E) } -2

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