Regular octagon ABCDEFGH has area n. Let m be the area of quadrilateral ACEG. What is nm?<spanclass=′latex−bold′>(A)</span>42<spanclass=′latex−bold′>(B)</span>22<spanclass=′latex−bold′>(C)</span>43<spanclass=′latex−bold′>(D)</span>532<spanclass=′latex−bold′>(E)</span>322