Question

the overall population of a species has increased. what could have occurred to allow this to happen?
the death - rate of the population is greater than the immigration.
the emigration rate is greater than the death rate.
the birth rate of the population is less than the death rate.
the immigration of the population is greater than the emigration.

Explanation:

Population change depends on birth - death rates and migration. If immigration exceeds emigration, more individuals are added to the population, which can cause an increase. Higher death rates than birth rates or higher emigration than death rates would not lead to an increase.

Answer:

The immigration of the population is greater than the emigration.