Although you unhelpfully didn't supply the following choices, the answer is
<u>the opportunity for former slaves to leave the U.S.</u>
Answer: The United Nations was more successful than the League of Nations. That shows the members of UN are more willing to participate and solve international conflicts and problems than LN. The United Nations was more successful than the League of Nations in maintaining world peace by comparing with their structure.
Explanation
1 and 4 are the best choices since The barbarian attacks killed many romans and the Huns sacked hundreds of cities in the Roman Empire and caused chaos. I also believe 4 is another reason for the decline, since the religion started about 400 years before the fall of the empire and sparked many different believes and divided the Empire through religion.
The correct answer is B: Immigration was based on the national origins quota system. The National Origins Act was a United States federal law that set the amount of immigrants from certain countries that were allowed to enter the U.S. Admission to the U.S was determined by ethnic identity and national origin. It reduced the number of southern and eastern Europeans and excluded Asians entering the country.
