C. Arachnida.
hope it's correct.
Answer:
3. B, D
Explanation:
A primary source is an animal that eats only plants. (herbivore) A secondary source is an animal that only eats herbivores (carnivores)
B has birds; which are food for carnivores, and fruits, nuts, and blossoms; which are food for herbivores.
D has vegetables and grains; which are food for herbivores, and meat; which is food for carnivores
The other options have only food for carnivores, or only food for herbivores, so the answer is 3
Well, depending on how long the migration is, many of the animals (mainly birds) could get sick and die, lowering the population. They could be shot by hunters, lowering the population. The children of the population could get left behind and lose their way, lowering the population. I'm not entirely sure how the population could grow other than them finding and staying with another group of their own kind. hope I was helpful! :)