The correct answer is B) Quota System.
A Quota System is a law that puts a specific limit on how many immigrants can come to a country. The US implemented this type of limit with the Immigration Act of 1924, setting a specific maximum number of immigrants allowed depending on the country.
All of the other option choices were different procedures and loopholes that people had to go through to enter the US at Ellis and Angel Island. This only stopped a small percentage of people from entering the US.
