Concept:The labour force grows when more people are available to work within a country, and it falls when people leave the country.
Explanation:A decrease in the death rate means fewer workers die, so the labour force can increase.
Better medical services improve health and reduce premature deaths, keeping more people available for work.
Immigration brings new people into the country, and they can join the labour force.
Emigration is the movement of people out of a country to settle permanently elsewhere.
When people emigrate, they leave the country, so the number of available workers decreases.
Therefore, emigration will NOT bring about an increase in the labour force.
Answer:D. Emigration.