Consider these functions: f(x) = -2x - 1 g(x) = Which statements, if any, are true about these functions? I. The function f(g(x)) = x for all real x.
II. The function g(f(x)) = x for all real x.
III. Functions f and g are inverse functions.

A. I only
B. II only
C. I, II, and III
D. None of the statements are true.