5. Let f be a function such that f (1) = -2 and f (5) -7. Which of the following conditions guarantees that f (c) =0 for some value c in the open interval (1,5)? (A) f is increasing on the closed interval [1,5] Neither (A), (C) nor (D) are required for f (c) = 0 for some c on the interval (1,5). (B) f is continuous on the closed interval [1,5] (B) must be true as it is a condition for the Intermediate Value Theorem. (C) f (3) =2.5 (D) f is decreasing on the closed interval [1,5]