Answer:
C. emigration
Explanation:
Definition of emigration is when more people leave a country or certain area more than people moving in, because of certain push factors, such as war, famine, disease, etc. (Factors that make people want to leave your area.)
Immigration is when people migrate to your country/area
Increased food supply means there is more people to feed, meaning more people will want to move to your country/area.
Diffusion is when people spread out in your country, taking up more space, leaving less living room for more people in the population.
