Which of the following is a possible reason for migration? a. microevolution b. diminished food supply c. increased ecosystem stability d. macroevolution

The possible reason for migration of animals is diminished food supply.The basic need of life is food.If there is a diminished food supply then the animals will start migrating to other places in search of food.There is always a fight for food among individuals of same or different species. There is no substitute of food as it is needed to perform all the important functions of body.As the amount of food diminishes the competition increases and the need for migration starts.

no i don't feel that humans have oversubscribed some medications