Transcript text: Given that $f(x)=x^{2}-6$ and $g(x)=3 x+4$, find $(f-g)(-2)$, if it exists.
Select the correct choice below and, if necessary, fill in the answer box to complete your choice.
A. $(f-g)(-2)=$ $\square$ (Simplify your answer.)
B. The value for $(f-g)(-2)$ does not exist.