D. exhausting a natural resource is not sustainable
External migration takes place for educational or economic reasons as well, but often, it is politically motivated. An international migrant is someone who moves to a different country. Simply, internal migration refers to the movement of people within a country.
Answer:
Inelastic
Explanation: When several close substitutes are available, consumers can easily switch from one good to another even if there is only a small change in price. Conversely, if no substitutes are available, demand for a good is more likely to be inelastic.
The Albert rift is the name of the boundary and the type of boundary is called converging boundaries.