A) Y because the line is flat, not going up or down. So, constant or no change in population
B) A positive correlation with introduction to animal A (because population is going up or increasing)
C)
1.New predator (due to Animal A eating them, meaning more of their predators are eating them)
2. Lack of food or food availability due to competition (from Animal A, e.g. if they eat the same food)
3. Introduction to a new disease (from Animal A)
Hope this helps!