Add the Polynomials $$\left( 4 x ^ { 6 } - 8 x ^ { 4 } + 8 x \right) + \left( 5 x ^ { 6 } - 2 x ^ { 4 } + 5 x \right)$$

Multiple Choice

Add the polynomials. Assume all variable exponents represent whole numbers.
- $$\left( 4 x ^ { 6 } - 8 x ^ { 4 } + 8 x \right) + \left( 5 x ^ { 6 } - 2 x ^ { 4 } + 5 x \right)$$

A) $9 x - 10 x ^ { 6 } + 13 x ^ { 4 }$
B) $13 x ^ { 6 } + 2 x ^ { 4 } - 3 x$
C) $12 x ^ { 11 }$
D) $9 x ^ { 6 } - 10 x ^ { 4 } + 13 x$