3.

Which of the following is a factor that can limit carrying capacity?
available nutrients (food, water)
available mates
competition
all of the above

All of the above.

All of the above are factors that can limit carrying capacity.

1. Available Nutrients (food, water): The availability of food and water resources can determine the maximum population size that an ecosystem can support.
2. Available Mates: The number of potential mates in a population can limit the reproductive success and growth rate of a species.
3. Competition: Interspecies or intraspecies competition for resources such as food, water, and shelter can limit the carrying capacity by reducing available resources for population growth.