What was the significance of the Immigration Acts of 1921 and 1924?:

A they limited immigration from Mexico for the first time.

B they created a category of "special immigrants," which included relatives of U. S. citizens living abroad.

C they made immigration requirements qualitative, rather than quantitative.

D they set quotas on immigration from certain areas of Europe, Asia, and Africa.

E they based annual quotas on a flat one-sixth of one percent of the national population in 1920.