Given parallelogram ABCD with E the midpoint of diagonal BD. Point E is connected to a point F in DA so that DF=31DA. What is the ratio of the area of triangle DFE to the area of quadrilateral ABEF?<spanclass=′latex−bold′>(A)</span>1:2<spanclass=′latex−bold′>(B)</span>1:3<spanclass=′latex−bold′>(C)</span>1:5<spanclass=′latex−bold′>(D)</span>1:6<spanclass=′latex−bold′>(E)</span>1:7