Correct answer: Biotic potential and environmental resistance determine the carrying capacity.
The biotic potential is defined as the maximum capacity of an organism to reproduce under adequate environmental conditions.
Environmental resistance is the resistance that inhibits or restrict the growth of an organism. It includes disease, competition, lack of food etc.
Both the factor biotic potential and environmental resistance is used to determine the carrying capacity of a species. It includes the maximum size of the population an environment can maintain such as habitat, food etc.