Why Does the Department of Homeland Security Need to Pay

Why does the Department of Homeland Security need to pay attention to global demographic data?

A) If a population is shrinking in size, that tends to foster desperate, potentially terrorist behavior.
B) If a population stops growing altogether, that usually means the people are in trouble and may want to immigrate to the United States.
C) A skyrocketing population means the country will have to expand and will be looking for territory to grab.
D) A skyrocketing population usually means insufficient jobs and high conflict which may breed terrorist activity.
E) A shrinking population suggests a country in need of immigrants, which may mean people moving out of the United States.