Let f (a) be a function such that f' (x) = 0 only at x = -1 and x = 4, f" (-1) = -1, f" (2) = -2, and f" (4) = 0. Which of the following is true? O f (x) has a point of inflection at x = 4 O f () has a relative (local) maximum at x = -1 O f (x) has a relative (local) maximum at x = 2 O f (x) has a relative (local) minimum at x = -1