What Do Demographers Mean When They Use the Concept of "Doubling

Multiple Choice

What do demographers mean when they use the concept of "doubling time" in their discussions of changes over time in the size of a population?

A) The number of years it would take for a population to double its size if its current birth rates and death rates are maintained.
B) The number of years it would take for a population to half its size if its current birth rates and death rates are maintained.
C) The number of months it would take for a population to double its size if its current birth rates and death rates are maintained.
D) The number of months it would take for a population to half its size if its current birth rates and death rates are maintained.
E) The number of years it would take for a population to become two times larger if its birth rates and death rates and immigration rates are maintained.