Which of the following is a requirement to become a U.S. citizen?

To become a U.S. citizen, one of the primary requirements is to be a resident for a certain period of time. Specifically, most applicants must have been lawful permanent residents (green card holders) for at least five years before they can apply for citizenship. This residency requirement ensures that applicants have sufficient ties to the United States and an understanding of its culture, government, and laws.

The other options present criteria that are not required for citizenship. For example, while having a job may be beneficial for integration into society, it is not a formal requirement for the naturalization process. Similarly, there is no educational requirement, such as having a high school diploma, for applying for U.S. citizenship, as individuals can demonstrate their eligibility through different means. Lastly, there is no minimum age of 30 years; applicants can begin the process at 18 years old, provided they meet other requirements such as residency and good moral character.