The arithmetic sequence a, a+d, a+2 d, a+3 d, \ldots, a+(n-1) d has the following properties:
- When the first, third, and fifth, and so on terms are added, up to and including the last term, the sum is 320 .
- When the first, fourth, seventh, and so on, terms are added, up to and including the last term, the sum is 224 .
What is the sum of the whole sequence?
Answer Choices
A. 656
B. 640
C. 608
D. 704
E. 672