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?

**Answer Choices**

A. 13

B. 16

C. 11

D. 12

E. 15