The correct answer is A. Show loyalty to their newly adopted country
Explanation:
Citizenship through naturalization occurs as an individual who was born in a different country becomes a citizen after a legal process and accomplishing different requirements. In this process, one of the requirements is to recite the Oath of Allegiance in which the newly naturalized citizen renounces to other citizenships and fidelity to foreign nations and promises to be loyal to the new country and follow the laws on it including the constitution. This has the purpose of making new citizens show they are citizens of a new country and would loyal to them or to show loyalty to their newly adopted country.
I hereby declare, on oath, that I absolutely and entirely renounce and abjure all allegiance and fidelity to any foreign prince, potentate, state, or sovereignty, of whom or which I have heretofore been a subject or citizen; that I will support and defend the Constitution and laws of the United States of America
It is technically a legal document, and it is binding. Which makes it unique from other types of documents. I’m not sure what you mean in regards to “tool”. But I would think it would be considered a reference document
The Organization of Petroleum Exporting Countries unites countries extracting petroleum that are involved in the Middle East, since no western states are members.