Industrialization in the 1800s significantly transformed life in the United States, and among the effects mentioned, the best response would be: It led to nativist feelings against the growing immigrant population.
As industrialization progressed, factories and industries attracted many immigrants seeking work, which in turn led to competition for jobs and resources. This influx often resulted in nativist sentiments, where established Americans felt threatened by the arrival of immigrants, leading to social tensions and discrimination.
Other options such as increased reliance on imported goods or isolationist views were not direct consequences of industrialization in the same way. Concerns about the population of enslaved people were also influenced by industrialization, but they are more complex and connected to evolving societal and economic factors, such as the rise of the abolitionist movement and economic dependency on slavery in the South. Thus, the nativist response most directly relates to the impact of industrialization during this period.