The red squirrel is a species of tree squirrel that can be found in parts of Europe and Asia. In an experiment, a researcher introduced small populations of red squirrels to two different ecosystems at the same time. One of the ecosystems was a large nature reserve. The other was a city park that was about one-fourth the size of the nature reserve. The graph below shows the red squirrel population in both ecosystems over three years. red squirrel population graph

The graph shows that while the red squirrel population was higher in the nature reserve than the city park, the city park still had a carrying capacity significantly more than one-fourth that of the nature reserve. Which statement could explain why the carrying capacity of the city park was higher than expected?
A.
The nature reserve is much larger than the city park, so its carrying capacity is greater.
B.
The city park contains fewer natural predators of the red squirrel than the nature reserve.
C.
The red squirrels in the city park face intense competition for a limited number of resources.
D.
The red squirrels in the nature reserve are better adapted to live in their environment.