The correct answer is option C that is, limiting factor.
In ecology, the limiting factor refers to the environmental circumstances, which restrict the abundance, growth, or distribution of a species or a population of organisms in an ecosystem.
In nature, the limiting factors like the water, availability of food, shelter, and space can modify the populations of animal and plants. Other limiting factors, like predation, competition for resources, and disease can also influence populations. If any of the mentioned limiting factors vary, the plant and animal populations get changed too.