The correct answer is A. Having a short hard beak is designed for breaking open hard nuts, while a slender beak is meant to drink nectar out of flowers. Doing the inverse (meaning slender beak for nuts, and hard beak for nectar) wouldn't work because the slender beak is to light to crack a nut, and the hard, strong beak isn't long enough to reach the center of a flower and get the nectar. Hope this helps!