4．如果ax²+bx+c>0的解集为?x?x<-2或x>4?,那么对于函数f(x)= ax²+bx+c应有                                                                    A．f(5)<f(2)<f(-1)                       B. f(2)< f(5)<f(-1)

C. f(-1)<f(2)< f(5)                        D. f(2)<f(-1)<f(5)