"A split in the Democratic Party" was one reason among the choices given in the question that transformed U.S. politics in the 1920s. . I hope that this is the answer that has come to help
After the Civil War, the United States went saw a <em>major transformation</em>, in which it transformed from being an agricultural society to an industrial one.
Many factors like the massive supplies of raw materials (like timber, iron ore, oil, and others), the development of new technology that made the tasks easier and faster, an important workforce constantly growing by the flow of immigrants, and a new breed of ruthless business leaders were fundamental into the major growth that manufacturing in that time and the following years.
Therefore, the correct answer is Manufacturing.
The best option from the list would be that Latinos in the United States come from different countries, but they all "<span>c. speak the same language", although a far better definition would be geographical. </span>
East Germany was one combatant
