Answer:
The correct answer is option d. "metapopulation".
Explanation:
A metapopulation is defined as a group of different populations living at different geographical regions but consisting of the same species. Usually the subpopulations of the metapopulation are separated by some barriers, but the individuals from one subpopulation interact with the individuals of the others regularly. This is the case of the Rocky Mountain Parmassian butterfly, whose individuals live on separate meadows in Alberta but can fly among meadows and interact among them.