That would be erosion. I know this because i spent years studying rocks and had straight passed all of it. Hope this helps. ;)
Can you show an image of the question?
The correct answer is coevolution.
The term is used to illustrate the conditions where two or more species communally influence each other’s evolution. For example, an evolutionary modification in the morphology of a plant may influence the morphology of a herbivore that consumes it, this, in turn, may influence the evolution of the plant that might influence the evolution of the herbivore and so on.
Coevolution most possibly takes place when distinct species have a close ecological association with each other. These ecological associations include parasite/host and predator/prey, mutualistic species, and competitive species.
