When Does a Change Take Place in a Demographic Transition

Multiple Choice

When does a change take place in a demographic transition? 

A)  Change occurs when either immigration or emigration changes the population growth pattern. 
B)  Change occurs when the birth rate drops below the death rate. 
C)  Change occurs when the economic development of a country changes the population growth pattern. 
D)  Change occurs when one-third of the population is under 15 years of age.