Answer:
A
Step-by-step explanation:
It's already given but here's a explaination.
The question asked how many children are being born in a country.
With the process of elimination...
D is definitely incorrect due to the answee being related to death.
C relates to a population and economy (At least what I belive)
B relates to the movement of people from one area to another.
A is the only answer that would make sense due to it relating to birth.