Final answer:
One must live in the United States for at least one year to become a US citizen.
Step-by-step explanation:
One of the requirements when becoming a US citizen is that you must live in the United States for at least one year. This is known as the residency requirement. It ensures that individuals have a basic understanding of the country and its values before becoming citizens. Being married or being under the age of 18 are not specific requirements for becoming a US citizen.
Learn more about Requirements for becoming a US citizen