What is the greatest real root of the equation x3−x2−x−31=0?<spanclass=′latex−bold′>(A)</span>23−2<spanclass=′latex−bold′>(B)</span>233−32<spanclass=′latex−bold′>(C)</span>33−11<spanclass=′latex−bold′>(D)</span>34−11<spanclass=′latex−bold′>(E)</span>None of above