Answer: C
Explanation:
If immigration and emigration numbers remain equal, decreased birthrate could cause a slowed growth rate
.
Decreased birthrate always affects the numbers in terms of population.The less births there are, the smaller the number of people. Even if the death rate remains constant a decreased birthrate will slow growth of population.
The patient could possibly have contracted some sort of foreign disease or might simply have an intolerance to a certain protein such as gluten with celiacs disease.