Which factor contributed to the declining immigration from Europe in the late 20th century?

The correct response highlights the impact of strengthening European economies on immigration patterns. During the late 20th century, many European countries experienced significant economic recovery and growth, particularly after the end of the Cold War. This economic prosperity created more job opportunities and improved living conditions within these countries, decreasing the incentive for individuals to emigrate to the United States.

As European economies stabilized and began to flourish, fewer Europeans felt the need to seek better opportunities abroad. This led to a natural decline in immigration toward the United States, as more people were able to find work and a high quality of life in their home countries.

In contrast, while political instability in Eastern Europe, changes in U.S. immigration policy, and increased acceptance of immigrants in Canada all played roles in shaping migration trends, the strengthening economies in Europe had a more direct and substantial impact on the desire and necessity for Europeans to immigrate to the U.S.