The correct answer is C. Infrastructure.
Explanation
Population growth is a phenomenon in which the number of human inhabitants of a country or area grows every year. This phenomenon is affected by the life expectancy that is the average of years people live; by the fertility rate that quantifies how many children on average women have, and by the immigration because if people arrive in a country the population grows. On the other hand, it can be affirmed that the infrastructure is not a factor that affects population growth or decline because this refers to buildings, roads, bridges, etc. in a country and this is not directly related to an increase in the population or affects the reproduction rates. So, the correct answer is C. Infrastructure.
