Concept:Abiotic factors are non-living environmental conditions that can limit or reduce a population.
Explanation:Control of human population involves both living and non-living factors.
Disease is caused by pathogens, so it is a biotic factor, not abiotic.
Famine is linked to food shortage, so it is not a purely abiotic factor.
Flooding and earthquakes are natural, non-living disasters.
They can directly cause death, injury, and displacement, thereby controlling human population size.
Hence, the pair of abiotic controlling factors is flooding and earthquake.
Answer:C. flooding and earthquake.