Economic opportunities, such as better job prospects and higher wages, are the primary reason why adults migrate from one place to another.

Access to healthcare is generally not a challenge faced by adult migrants, as most countries provide healthcare services to all residents, regardless of their immigration status.

Migration can have both positive and negative impacts on the sending country. It can lead to a brain drain, reduce the population density, and boost the economy through remittances.

Urbanization is the term used to describe the movement of people from rural areas to urban areas.

Climate change is not a direct factor that influences adult migration, although it can indirectly affect migration patterns through its impact on economic conditions and political stability.

Immigration is the term used to describe the movement of people from one country to another.

Rural-urban migration is not a type of migration, but rather a specific pattern of migration that involves the movement of people from rural areas to urban areas.

Internal migration is the term used to describe the movement of people from one place to another within the same country.

Social cohesion is not a positive impact of migration on the receiving country, as migration can sometimes lead to social tensions and conflicts.

Emigration is the term used to describe the movement of people out of a country.

Access to education is generally not a challenge faced by adult immigrants, as most countries provide equal access to education for all residents, regardless of their immigration status.

Migration can have both positive and negative impacts on the receiving country. It can increase the population density, boost the economy through remittances, and lead to a brain gain.

Family reunification is not a factor that influences adult emigration, as it is typically a factor that influences immigration.

Ruralization is the term used to describe the movement of people from urban areas to rural areas.

Voluntary migration is not a type of migration, but rather a characteristic of migration that describes the situation where people choose to migrate of their own free will.