If a \equal{} \log_8 225 and b \equal{} \log_2 15, then a, in terms of b, is:
<spanclass=′latex−bold′>(A)</span>2b<spanclass=′latex−bold′>(B)</span>32b<spanclass=′latex−bold′>(C)</span>b<spanclass=′latex−bold′>(D)</span>23b<spanclass=′latex−bold′>(E)</span>2b