Point R is 10 m north of point A. Point K is exactly in the middle of the points R and A. Point N is 7 m east of point A. Point M is 7 east of point K. Point S is 6 m north of point M. What is the distance between the points S and N?
A. 13 m
B. 11 m
C. 12 m
D. None of these
