Which of the following statements about the Demographic Transition Model are true?

1. In Stage One of the demographic transition, high birth and death rates lead to stable population growth.
2. Stage Two is characterized by a decline in both birth rates and death rates, resulting in slow population growth.
3. Stage Four of the demographic transition is marked by both low birth and death rates, leading to a stabilized population with low growth rates.
4. A hypothesized Stage Five involves fertility rates dropping below replacement levels in many countries.