I am pretty sure that the actual answer hides in the question itself, therefore I'd choose the second option. According to the phrase "he more successful of the two", it definitely should be B. Competition.
Natural selection is what the process is called.I hope this helps.
There was more erosion in the Colorado Rockies scenario where there was steady rain compared to the scenario in the same area where there was only a drizzle. There is more erosion because the steady rain increased the volume of the river more than the drizzle did.
The answer is Sieve. hope that helped
