Which of the Following Statements Gives an Example of Coevolution

Which of the following statements gives an example of coevolution?

A) Two unrelated species form at the same time after ancestral species populate a newly formed volcanic island.
B) Two closely related mice species on different mountaintops in the southwest United States both adapt the same trait because food sources are similar.
C) An ant species and a plant species both develop adaptations in response to changes in the other species.
D) A wild cat species and a wild dog species both have similar bacteria living in their guts, which allow them to produce vitamin K.