A paper is in a square form whose one side is 20 cm. Two semi circles are drawn on its opposites as diameters. If these semi circles are cut down what is the area of the remaining paper?

A. (400 – 100π) cm^2</sup
B. (400 – 2π) cm^{2</sup

C. (400 – 200π) cm^{2</sup

D. 200π cm^2</sup}}