The diagram below shows the elements in a cycle: A cycle diagram with three boxes is shown. One box reads, Immigration. An arrow points from that box to a second box that reads, Industrialization. An arrow points from the second box to a third box that contains a question mark. Which term completes this graphic organizer, and why? a Unionization, because immigrants won major reforms from industries by forming their own labor unions b Urbanization, because immigrants moved to areas with industries to find jobs, spurring the growth of cities c Naturalization, because industries often gave immigrant employees the opportunity to become American citizens d Unemployment, because immigrants were not able to work in most industries, leading to high jobless rates