The function f : A → B defined by f(x)=−x^2+6x-8 is a bijection, if A. A = (- ∞, 5] and B = (-∞, 1] B. A = [- 3, ∞] and B = (-∞, 1] C. A = (–∞, 3] and B = [1, ∞) D. A = [3, ∞) and B = [1, ∞)