Its B.
If [tex]f(x)=4x+1[/tex] and [tex]g(x)=x^2-5[/tex] then, [tex](\frac{g}{f})(x)=\frac{x^2-5}{4x+1}[/tex] and [tex]x\neq-\frac{1}{4}[/tex] because if x were [tex]-\frac{1}{4}[/tex] then you would have division by 0.
Hope this helps.
