Concept:The features described are typical of birds and reptiles.Explanation:Birds and reptiles both have scales or scale-derived structures like feathers.They lay eggs with tough, protective shells.They share a similar bony structure of the head, including a single occipital condyle.Fishes have scales but do not lay shelled eggs.Molluscs do not have scales or a bony skull.Therefore, the characteristics point only to birds and reptiles.Answer:A. birds and reptiles