Questions 5-6: Consider a function fx), differentiable on [-1, 5]. Suppose f(1) = f(4) = 0 and f(3) = 6. 5. Which of the following is NOT necessarily true?; * O (A) f' (3) exists O (B) There exists a point c on [1, 4] such that f ' (c) = 0 O (C) There exists a point d on [1, 3] such that f(d) = 5 O (D) All of the above are always true