Which of the following statements is TRUE? O a. If f(a) and g(x) are differentiable functions defined on the closed interval [a, b], and f(x) attains its global maximum at x = c and g(x) attains its global maximum at x = d, then the function f(x) · g(x) attains its global maximum on [a, b] at x = cºd. O b. All of the statements are false. a O c. Every local maximum is a global maximum d. The global maximum value of a differentiable function f(x) on a closed interval (a, b) must occur at a critical value or an endpoint e. The critical points of f'(2) are same as the critical points of f(x)