Which of the following is an example of a density-dependent limiting factor?

A density-dependent limiting factor is a factor that influences a population's growth in a manner that is related to the density of that population. In this context, disease is indeed a prominent example. As a population becomes denser, the likelihood of disease transmission among individuals increases, which can lead to higher mortality rates. This effect makes the survival and reproduction rates of the population heavily dependent on its density; in denser populations, more individuals are likely to come into contact with pathogens, which can exacerbate the spread and impact of diseases.

In contrast, other factors such as natural disasters, climate change, and pollution are considered density-independent limiting factors. These factors affect populations regardless of their density; for example, a natural disaster can decimate a population without regard to how many individuals are present. Similarly, climate change can alter habitats and available resources universally, impacting populations irrespective of their numbers. Pollution can affect all individuals in an environment without being influenced by their population size. Hence, disease stands out as a density-dependent limiting factor due to its direct relationship with population density.