Though animals may (or probably) be all linked by one source, organisms still have their own types of sequences in their DNA. Because of this, these form different species/organisms in the environment and create variety. For example if the DNA of a Red bird and a blue bird bred, it is possibly that they could create a newer variety of birds that could be a mixed species, having their own type of DNA, that is altered from the red and blue bird(s).
Most animals in Animalia have backbones, but not all. The correct answer would be C, because all organisms in Animalia are heterotrophs which means that they depend on other organisms (like animals and plants) for food.
