The density of a population in a given habit during a given period, fluctuates due to changes in certain basic processes. On this basis, fill up boxes `A` and `B` in the given flow chart with correct option.

Options

A. `A-` Natality, `B-` Mortality
B. `A-` Immigration, `B-`Emigration
C. `A-`Natality, `B-`Immigration
D. Both (a) and (b)

Answer

D

Explanation

Natality and Immigration add to the population density Mortality and emigration decrease the population density.