The expression x2−y2−z2+2yz+x+y−z has:<spanclass=′latex−bold′>(A)</span>no linear factor with integer coeficients and integer exponents<spanclass=′latex−bold′>(B)</span>the factor −x+y+z<spanclass=′latex−bold′>(C)</span>the factor x−y−z+1<spanclass=′latex−bold′>(D)</span>the factor x+y−z+1<spanclass=′latex−bold′>(E)</span>the factor x−y+z+1