The majority of immigrants and rural migrants who moved to American cities at the turn of the twentieth century became part of the working poor, struggling with low wages and difficult living conditions. This experience reflects the challenging nature of urban migration during that time. Therefore, the correct answer is B. working poor.
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Most immigrants and rural migrants who moved to American cities during the early twentieth century became part of the working poor, facing economic hardships. While some later improved their socioeconomic status, many began their journey in challenging conditions. This demonstrates the complexities of migration and urbanization in America's history. ;