Consider a real valued continuous function f(x) defined on the interval [a, b). Which of the followin statements does not hold(s) good? (A) If `f(x) ge 0` on [a, b] then `int_a^bf(x) dx le int_a^bf^2(X)dx` (B) If f (x) is increasing on [a, b], then `f^2(x)` is increasing on [a, b]. (C) If f (x) is increasing on [a, b], then `f(x)ge0` on (a, b). (D) If f(x) attains a minimum at x = c where `a lt c lt b`, then `f'(c)=0`.