If 78 is divided into three parts which are proportional to 1,31,61, the middle part is:
<spanclass=′latex−bold′>(A)</span>931<spanclass=′latex−bold′>(B)</span>13<spanclass=′latex−bold′>(C)</span>1731<spanclass=′latex−bold′>(D)</span>1831<spanclass=′latex−bold′>(E)</span>26