For the positive integer n, let ⟨n⟩ denote the sum of all the positive divisors of n with the exception of n itself. For example, ⟨4⟩=1+2=3 and ⟨12⟩=1+2+3+4+6=16 What is ⟨⟨⟨6⟩⟩⟩?<spanclass=′latex−bold′>(A)</span>6<spanclass=′latex−bold′>(B)</span>12<spanclass=′latex−bold′>(C)</span>24<spanclass=′latex−bold′>(D)</span>32<spanclass=′latex−bold′>(E)</span>36