Respuesta :

[tex]( \frac{f}{g})(x) [/tex] means the ratio of f(x) with g(x) i.e. function f(x) divided by the function g(x).

[tex]( \frac{f}{g})(x)= \frac{f(x)}{g(x)} \\ \\ = \frac{4x+1}{ x^{2} -5} [/tex]

The correct option is B.
The restriction of the domain is made so that the denominator is never zero and the expression is never undefined. In case of such questions, domain must be taken into account.