Which term describes a pond that can only support a population of 100 sunfish?

Your answer is C, carrying capacity
That is the factor that keeps it from allowing there to be more fish. Any more would upset it's balance.
An abiotic factor is a nonliving thing that interacts with an environment
A trophic level is where a species stands on the energy pyramid
Exponential growth would mean that the pond's population grows by a certain factor
The question is worded strangely, but it should be C