Wolves are a predator they hunt in pacts so A is out of the question C isn't right either They'll get hunted down more same reasoning with that and D would mean they are starting to overpopulated ( B) is your answer
If the population of wolves had a significant growth between 1970-1975 we can consider that the predator level of these animals was high, then the population of animals that are prey of these animals were at risk of decreasing and that is what happened. In the graph shown in the question above, we can see that the moose population decreased because wolves, like their predators, were in greater numbers and were able to suppress the moose population due to predatorism.
The very primitive organism is the oldest because, over time, organisms gradually evolved into more complex organisms. First came the primitive organism, then it evolved into the more complex one, or the younger fossil.