Concept:A declining population is one that steadily grows smaller because people are leaving or the number of births is not enough to replace deaths.
Explanation:Population size depends on births, deaths, immigration, and emigration.
Emigration is the act of moving out of one's home country to live permanently in another country.
When a high rate of emigration occurs, the number of residents in the country falls continuously.
At the same time, if the remaining population does not have enough births to replace those losses, the total population shrinks.
Thus, a declining population is mainly shown by a continuing reduction in the number of people living in the country.
It is not determined by the amount of goods produced or by the income contributed to the nation.
Answer:The correct option is A: experiencing a high rate of emigration.