Add the Polynomials $$\left( - 9 x ^ { 7 } + 18 x ^ { 6 } - 13 \right) + \left( 3 x ^ { 7 } + 16 x ^ { 6 } - 9 \right)$$

Multiple Choice

Add the polynomials. Assume all variable exponents represent whole numbers.
- $$\left( - 9 x ^ { 7 } + 18 x ^ { 6 } - 13 \right) + \left( 3 x ^ { 7 } + 16 x ^ { 6 } - 9 \right)$$

A) $- 6 x ^ { 7 } + 34 x ^ { 6 } - 22$
B) $6 \times 13$
C) $- 6 x ^ { 7 } + 25 x ^ { 6 } + 4$
D) $- 6 x ^ { 7 } + 34 x ^ { 6 } + 4$