For the Given Pair of Functions, Find the Requested Function $f(x)=3 x-4$

Multiple Choice

For the given pair of functions, find the requested function.
- $f(x) =3 x-4$ and $g(x) =-9 x^{2}-9 x+9 ;(f+g) (x)$

A) $-10 x^{2}-6 x-5$
B) $9 x^{2}-6 x-13$
C) $-9 x^{2}+6 x+5$
D) $-9 x^{2}-6 x+5$