Which of the following statements is true for inverse functions f(x) and g(x)?
A) (f•g)(x) = (g•f)(x) = 1
B) (f•g)(x) = (g•f)(x) = f(x)
C) (f•g)(x) = (g•f)(x) = 0
D) (f•g)(x) = (g•f)(x) =x