Which of the Following Statements About the Demographic Transition Is

Which of the following statements about the demographic transition is correct?

A) During the transition, death rates increase due to sedentary lifestyles linked to industrialization
B) During the transition, death rates drop first, then there is a lag time before birth rates drop
C) During the transition, birth rates drop first, which leads to lower mortality overall
D) During the transition, changes in death rates and birth rates occur in tandem