An example of coevolution is A. predators killing their prey. B. one species moving out of an area to find new resources. C. host species becoming more vulnerable to parasitism. D. pine tree evolving thicker pinecones to reduce consumption by squirrels after the squirrels evolved stronger jaws to eat the pinecones.

D. pine tree evolving thicker pinecones to reduce consumption by squirrels after the squirrels evolved stronger jaws to eat the pinecones.

Explanation:

An example of coevolution would be pine tree evolving thicker pinecones to reduce consumption by squirrels after the squirrels evolved stronger jaws to eat the pinecones.

Coevolution is a process in which two species of organisms evolve together complementarily, with the evolution of one affecting how the other evolve and vice versa.

Evolution in itself is defined as the gradual change in the characteristics of organisms over a period of time.

Organisms that coevolve usually have a kind of relationship with one another. Assuming organism A and B are in coevolution, a change in organism A will lead to a complimentary change in organism B and vice versa.

Hence the correct option that exemplify coevolution is option D.