Final answer:
An example of a density-independent population control is d) Drought, which affects members of a population regardless of density, as compared to density-dependent factors which vary with population density. The correct option is D.
Step-by-step explanation:
The example of a density-independent population control from the options provided is d) Drought. Density-independent factors influence the mortality of a population regardless of its density and are typically physical or chemical in nature (abiotic).
Some examples of density-independent factors include weather, natural disasters, and pollution, such as a forest fire or a drought, which would affect members of a population no matter how dense the population is. In contrast, density-dependent factors like predation, disease, and competition are biotic and have varying effects depending on the population's density.