The best explanation regarding dual citizenship in the United States is:
The U.S. permits dual citizenship for naturalized citizens from other countries.
While the U.S. generally does not encourage dual citizenship, it does recognize that dual citizenship can occur, especially in the case of naturalized citizens. Natural born citizens are also not expressly prohibited from holding dual citizenship; however, the rules can be complex depending on the laws of other countries involved. The other statements provided are inaccurate regarding the rights and obligations of dual citizens in the U.S.