Which will probably decrease population density? a. normal rainfall b. fewer predators c. high birth rate d. forest fire

D. forest fire

Population density can be defined as the measurement of population of a species per unit area. It is the quantitative measurement noted in numbers. It is applied to all the living organisms and most commonly to humans. A limiting factor is the one which can limit the growth, abundance and distribution of a members of species in a habitat.  

The forest fire is the limiting factor which is capable enough to decrease the population density of the species. As, fire the acquire a large surface area of a location or habitat and can kill a large number of individuals hence affecting the population density.  

the answer to your question is b