Stones are numbered $1,2,3,4,5,6,7,8,9,10$. Three groups of stones can be selected so that the sum of each group is 11 . For example, one arrangement is $\{1,10\},\{2,3,6\}$, $\{4,7\}$. Including the example, how many arrangements are possible?
(A) 13
(B) 16
(C) 11
(D) 12
(E) 15