The answer is false.
The answer is d. increased biodiversity.
Migration is an adaptation that helps animals to survive. There are many reasons for migration leading to temporary or permanent migration.
For example, if climate changes or food supply reduces, some animals will move to the area with adequate climate or enough food, respectively. These are examples of temporary migration since those animals will not return to their original area of living.
Some animals, on the other hand, move to reproduce, such as the Atlantic Salmon. So, they migrate seasonally, when is the right time for reproduction. After that, they return to their original area of living.
