Can natural selection occur in both small populations and large populations

The natural selection can occur in both small and large populations

Explanation:

In a larger population, the natural selection is not so visible because of the larger gene pool. It would take a pretty much longer time to show that there have been changes that will catch the eye, this will not be seen immediately, whereas the smaller population can see changes distinctively.  

The recessive gene at the time of natural selection may not get the advantage. The dominant gene will have far better chances of survival and thriving as well. The survivors in the broader population would also be less diverse, whereas the smaller community will end up with lesser people but are visible diverse.                                  

a: the sheep and waste material both release carbon into the atmosphere.

the correct answer is:

a population changes in response to a change in the environment.