a ) is wrong!
Here is your entire sequence grouped in "twos"
(10201 -9409, 8649 -7921, 7225 -6561, 5929 -5329, 4761 -4225, 3721 -3249, 2809 -2401, 2025 -1681, 1369 -1089, 841 -625, 441 -289, 169 -81, 25 -1)
What is the difference between each pair beginning with first? The following:
(792, 728, 664, 600, 536, 472, 408, 344, 280, 216, 152, 88, 24) - This is an arithmetic sequence. How do you sum it up?
[F + L] / 2 * N (number of terms) =Sum, where F=First term, L=Last term, N =Number of terms.
[792 + 24] / 2 * 13 =5,304 - And that is it!.