Find $\lim _{x \rightarrow 3}[g(x)-f(x)]$ For $f(x)=3 x^{3}$ And $g(x)=\frac{\sqrt{x^{2}+2}}{5 x^{2}}$

Multiple Choice

Find $\lim _{x \rightarrow 3}[g(x) -f(x) ]$ for $f(x) =3 x^{3}$ and $g(x) =\frac{\sqrt{x^{2}+2}}{5 x^{2}}$ .

A) $\frac{\sqrt{11}}{45}-81$
B) $\frac{\sqrt{3}}{5}-81$
C) $\frac{9 \sqrt{11}}{5}$
D) $\frac{\sqrt{3}}{5}+81$
E) limit does not exist