77 stones weighing 1,2,…,77 grams are divided into k groups such that total weights of each group are different from each other and each group contains less stones than groups with smaller total weights. For how many k∈{9,10,11,12}, is such a division possible?<spanclass=′latex−bold′>(A)</span>4<spanclass=′latex−bold′>(B)</span>3<spanclass=′latex−bold′>(C)</span>2<spanclass=′latex−bold′>(D)</span>1<spanclass=′latex−bold′>(E)</span>None of above