**Source: GMAT Paper Tests**

The figure above shows a rectangular parcel of undeveloped land partitioned into four regions, P, Q, R, and S. In square meters, the area of square region Q is x^2, the area of rectangular region R is 5x, and the area of rectangular region P is 4x. What is the area, in square meters, of rectangular region S?

A. \(x^2-x\)

B. \(x^2+9x\)

C. \(20x-x^2\)

D. \(9\)

E. \(20\)

The OA is E