Answer;
B.The deer population experienced a rapid decline due to a parasite.
Step-by-step explanation;
-Limiting Factor is an environmental factor that tends to limit population size. Limiting factors may be density dependent or density independent. The density dependent factors are factors whose effects on the size or growth of the population vary with the population density. There are many types of density dependent limiting factors such as; availability of food, predation, disease, and migration.
-Density independent factors can affect a population no matter what it's density is. For example: natural disasters, temperature, sunlight, human activities, physical characteristics and behaviors of organisms affect any and all populations regardless of their densities.