Let n be the number of pairs of values of b and c such that 3x+by+c=0 and cx−2y+12=0 have the same graph. Then n is:<spanclass=′latex−bold′>(A)</span>0<spanclass=′latex−bold′>(B)</span>1<spanclass=′latex−bold′>(C)</span>2<spanclass=′latex−bold′>(D)</span>finite but more than 2<spanclass=′latex−bold′>(E)</span>greater than any finite number