If s=(1+2−321)(1+2−161)(1+2−81)(1+2−41)(1+2−21), then s is equal to<spanclass=′latex−bold′>(A)</span>21(1−2−321)−1<spanclass=′latex−bold′>(B)</span>(1−2−321)−1<spanclass=′latex−bold′>(C)</span>1−2−321<spanclass=′latex−bold′>(D)</span>21(1−2−321)<spanclass=′latex−bold′>(E)</span>21