Add or Subtract as Indicated $\begin{array}{c}6 m^{3}-8 m+5 \\ -2 m^{3}+12 m+8\end{array}$

Multiple Choice

Add or subtract as indicated.
-Add.
$\begin{array}{c}6 m^{3}-8 m+5 \\ -2 m^{3}+12 m+8\end{array}$

A) $4 m^{3}+4 m+13$
B) $-34 m+20 m+3$
C) $8 \mathrm{~m}-20 \mathrm{~m}-3$
D) $-33 m^{3}-4 m-13$