JEE Math Practice Question

Let f : R $$\to$$ R be a function defined by f(x) = (x $$-$$ 3)n1 (x $$-$$ 5)n2, n1, n2 $$\in$$ N. Then, which of the following is NOT true?

1. A.For n1 = 3, n2 = 4, there exists $$\alpha$$ $$\in$$ (3, 5) where f attains local maxima.
2. B.For n1 = 4, n2 = 3, there exists $$\alpha$$ $$\in$$ (3, 5) where f attains local minima.
3. C.For n1 = 3, n2 = 5, there exists $$\alpha$$ $$\in$$ (3, 5) where f attains local maxima.
4. D.For n1 = 4, n2 = 6, there exists $$\alpha$$ $$\in$$ (3, 5) where f attains local maxima.