FERMAT 2003 Problem 4

In the diagram, the numbers 1 to 10 are placed around a circle. Sandy crosses out 1, then 4, and then 7. Continuing in a clockwise direction, she crosses out every third number of those remaining, until only two numbers are left. The sum of these two numbers is

Image

Answer Choices
A. 13
B. 10
C. 8
D. 14
E. 17