Which of the Following Is Most Accurate About the Period

Which of the following is most accurate about the period between the Civil War and World War I?

A) Many people moved to urban areas because the death rates were much lower there than in rural areas.
B) Labor unions increased their membership significantly, and by the end of the period about 10 percent of the total labor force was in unions.
C) Women's participation in the labor force decreased because they did not want to work in the industrial sector.
D) The large increase in population was caused, in part, by significant increases in the birth rate.