How many ordered pairs of positive integers (x,y) are there such that y2−x2=2y+7x+4?<spanclass=′latex−bold′>(A)</span>3<spanclass=′latex−bold′>(B)</span>2<spanclass=′latex−bold′>(C)</span>1<spanclass=′latex−bold′>(D)</span>0<spanclass=′latex−bold′>(E)</span>Infinitely many