Which of the Following Events Contributed Most to an Increase

Which of the following events contributed most to an increase in the number of African American public officials?

A) The legal end of segregation in public schools
B) The ratification of the Nineteenth Amendment
C) The passage of major civil rights legislation in the 1960s
D) The refinement of the constitutional requirements for office in the latter 1800s
E) The lowering of the legal voting age to 18