Let's recall what Charles Darwin found:
He stated that natural selection plays a huge role in evolution. He claimed that organisms that had the best traits well-adapted for their specific ecosystem would be able to survive the longest (the most fitness and also known as "survival of the fittest").
Also recall what happens in an ecosystem and food webs as well as the logistical growth equation:
Ecosystems have only so many amounts of resources, or limited resources. Therefore, organisms within the same ecosystem will compete for these resources. These organisms will struggle and fight to survive. They either adapt or they get killed off.
Therefore, the best answer choice that doesn't describe Darwin's statements about evolution is answer choice D.