Find the sum of the polynomials below:

\[(8x^9 + 6x^6 - 2x + 6) + (9x^9 + 4x^6 + 9x + 7)\]

A. \(17x^9 + 10x^6 + 7x + 13\)
B. \(10x^9 + 17x^6 + 7x + 13\)
C. \(72x^9 + 24x^6 - 18x^2 + 13\)
D. \(17x^9 + 10x^6 - 7x + 13\)