Do rational expressions contain logarithmic functions? a. always b. sometimes c. never

By definition, rational expression is the ratio of two polynomial function Q(x) and P(x), where P(x) should not be zero. Polynomial function is defined as continuous for all real number. But, Logarithmic function is continuous only for any value of x>0. Hence,Rational expression SOMETIMES contain logarithmic functions and it should not be located at the denominator.

For me i think it'll land on blue