If a5+5a4+10a3+3a2−9a−6=0 where a is a real number other than −1, what is (a+1)3?<spanclass=′latex−bold′>a)</span>1<spanclass=′latex−bold′>b)</span>33<spanclass=′latex−bold′>c)</span>7<spanclass=′latex−bold′>d)</span>8<spanclass=′latex−bold′>e)</span>27