Answer: b: the birth rate decreased, while the death rate increased.
Birth rate can be define as the total number of live births per 1000 in a population in a year or period. Death rate can be defined as the number of individuals die per 1000 in a population in a year or period. Immigration rate is the number of individuals who enter a new place for resources in a period. Emigration rate is the movement of individuals from one location to other in a particular time. Carrying capacity is the ability of the habitat to sustain life of population of one or more species by availing resources like food, water, shelter etc.
If the immigration rate increases, while the death rate decreases in this case death rate can decrease the population but this loss can be compensated with increase in immigration rate. Hence, there will be no net decrease in the overall population of the species.
If the carrying capacity increased, while the immigration increased, in this case both factors will be responsible for increase in the overall population of the species.
If the emigration increased, while the birth rate increased, in this case emigration will lower the population size but increase in the birth rate will compensate for the loss. Hence, there will be no net decrease in the overall population of the species.
Lastly, the birth rate decreased, while the death rate increased. Both of these factors will contribute to overall decrease in the population of the species.
