The regular octagon A B C D E F G H has its center at J. Each of the vertices and the center are to be associated with one of the digits 1 through 9 , with each digit used once, in such a way that the sums of the numbers on the lines A J E, B J F, C J G, and D J H are equal. In how many ways can this be done?

**Answer Choices**

A. 384

B. 576

C. 1152

D. 1680

E. 3456