Limiting factors refers to those factors that limit the size of a population. The factors can be of two types:
• Density-dependent limiting factors and
• Density-independent limiting factors.
A population grows exponentially till all the resources are available in the sufficient amount. But, as the population density increases, the resources become limited and the population growth slows down.
Effects of Logistic growth and carrying capacity are seen, as a result of limiting resources.
Logistic growth is seen, when population’s growth slows down, but its limiting factor makes the growth to slow down.
Hence, the correct option is (a) limiting factor.