For some positive integer k, the repeating base-k representation of the (base-ten) fraction 517 is 0.23k=0.232323...k. What is k?
<spanclass=′latex−bold′>(A)</span>13<spanclass=′latex−bold′>(B)</span>14<spanclass=′latex−bold′>(C)</span>15<spanclass=′latex−bold′>(D)</span>16<spanclass=′latex−bold′>(E)</span>17