1please give an example..

15 n Let f and g be any two functions defined o s. R and f og denote composition of functions Let a e R be such that lim(fo g)x) exists X-a then (a) Both lim f(x) and lim g(x) exists Xa a (b) Either lim f(x) or lim g(x) exists a X-a (c) It is possible that lim f(x) and -a lim g (x) both does not exists a (d) None of these