The largest proportion of federal revenues comes from taxes from the American citizen population. There are other large sources of revenue, but the current tax code makes for a great deal of revenue.
Answer: A, the First Amendment
Explanation:
The First Amendment states that Americans have freedom of speech, press, religion, assembly, and petition. All of these but religion are social movements that could change government regulations or laws.
The Mississippians were a native American culture that inhabited the Mississipi River Valley and surrounding areas from 9th till 16th century. Their culture was unique in that they created Mounds, that is man-made hills, many of them are still existing today.