Last summer 30% of the birds living on Town Lake were geese, 25% were swans, 10% were herons, and 35% were ducks. What percent of the birds that were not swans were geese?
<spanclass=′latex−bold′>(A)</span>20<spanclass=′latex−bold′>(B)</span>30<spanclass=′latex−bold′>(C)</span>40<spanclass=′latex−bold′>(D)</span>50<spanclass=′latex−bold′>(E)</span>60