2001 AMC 12 Problem 3

The state income tax where Kristin lives is levied at the rate of p\% of the first \$28000 of annual income plus (p + 2)\% of any amount above \$28000. Kristin noticed that the state income tax she paid amounted to (p + 0.25)\% of her annual income. What was her annual income?

\text{(A)}\ 28000\qquad \text{(B)}\ 32000\qquad \text{(C)}\ 35000\qquad \text{(D)}\ 42000\qquad \text{(E)}\ 56000$

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