This is the way in which a species' population grow and shrink over time. \

Population Dynamic

Explanation:

The population dynamic refers to the study of the magnitude and the age of a population in a particular dynamic system. It determines the growing and shrinkage of an existing population over a definite period of time and the factors that are responsible for these changes.

The change in population density is given by,

Population density change=(Births + Immigration) - (Deaths + Emigration), where the events namely birth, immigration, death and emigration directly affects the population density.

because of

the correct answer, according to e2020, is the second choice there is an occluded front in region a and a cold front in region b.