What term describes the legal process to obtain citizenship?

Naturalization is the legal process through which a non-citizen can acquire the citizenship of a country. This process typically involves fulfilling specific requirements, such as establishing residency, demonstrating an understanding of the country's language and government, and taking an oath of allegiance.

In the context of the United States, naturalization applies to individuals who have immigrated legally and wish to become citizens, granting them rights and responsibilities associated with citizenship, including the right to vote and hold public office.

The other terms do not pertain to the process of acquiring citizenship specifically. Civic duty refers to the responsibilities of citizens, such as voting and participating in civic life, while a constitutional amendment involves a formal change to the Constitution, which does not directly relate to the citizenship process. Immigration describes the movement of people into a country, but it does not necessarily result in citizenship without the naturalization process.