How many positive integers less than 1000 are there such that they cannot be written as sum of 2 or more successive positive integers?<spanclass=′latex−bold′>(A)</span>6<spanclass=′latex−bold′>(B)</span>10<spanclass=′latex−bold′>(C)</span>26<spanclass=′latex−bold′>(D)</span>68<spanclass=′latex−bold′>(E)</span>72