Add or Subtract as Indicated $\left(4 n^{5}+4 n^{3}+9 n\right)+\left(3 n^{5}+2 n^{3}+6 n\right)$

Multiple Choice

Add or subtract as indicated.
- $\left(4 n^{5}+4 n^{3}+9 n\right) +\left(3 n^{5}+2 n^{3}+6 n\right)$

A) $12 n^{5}+6 n^{3}+10 n$
B) $7 n^{5}+6 n^{3}+15 n$
C) $7 n+6 n^{5}+15 n^{3}$
D) $28 n^{9}$