Which Is a Correct Statement Regarding Mid-Century Immigrants

Which is a correct statement regarding mid-century immigrants?

A) Germans fled a severe potato famine.
B) Germans, Irish, and Scandinavians came seeking improved economic opportunity.
C) The Irish and Scandinavians tended to come as families with some resources, but the Germans were usually single men from impoverished backgrounds.
D) Immigration swelled to its highest levels during periods of economic downturns in the U.S., when employers sought cheaper labor.