Provide an Appropriate Response $f(x)=x^{2}-3$ And $g(x)=3 x+9$ Find $(f+g)\left(\frac{1}{2}\right)$

A)

Provide an appropriate response.
-Let $f(x) =x^{2}-3$ and $g(x) =3 x+9$ . Find $(f+g) \left(\frac{1}{2}\right)$ .

A) $\frac{35}{4}$

B) $\frac{31}{4}$

C) $\frac{15}{2}$

D) 8