What happens to population in stage two of the demographic transition theory?

The correct answer is the second population increases. 

The demographic transition model describes how a population of a country transitions from high birth and death rates to low birth and death rates, as a country becomes more industrialized. This transition occurs through five stages (refer to attached image). In the second stage of the demographic transition model, a country's population increases because birth rates continue to increase, while death rates fall considerably. 

3. i would say one, but one is not prime nor composite.