Of the 500 balls in a large bag, 80% are red and the rest are blue. How many of the red balls must be removed so that 75% of the remaining balls are red?<spanclass=′latex−bold′>(A)</span>25<spanclass=′latex−bold′>(B)</span>50<spanclass=′latex−bold′>(C)</span>75<spanclass=′latex−bold′>(D)</span>100<spanclass=′latex−bold′>(E)</span>150