Inside square ABCD with side s, quarter-circle arcs with radii s and centers at A and B are drawn. These arcs intersect at point X inside the square. How far is X from side CD?<spanclass=′latex−bold′>(A)</span>21s(3+4)<spanclass=′latex−bold′>(B)</span>21s3<spanclass=′latex−bold′>(C)</span>21s(1+3)<spanclass=′latex−bold′>(D)</span>21s(3−1)<spanclass=′latex−bold′>(E)</span>21s(2−3)