Your answer is going to be D
As you talk in animals
nucleus/ plasma membrane / mitochondria
if you talk in plants
nucleus / the cell / plastid / mitochondria
None of the above
Consumers by definition produce their own food (from sunlight)
Carnivores feed on other animals, herbivores feed on plants, plants create their own food. whereas scavengers feed on dead animals etc
Littering, hunting specific endangered species, honestly there are tons of things so the easiest one would be littering because if animals eat certain things it can kill them.
