Final answer:
A person may gain U.S. citizenship by naturalization if they are born on a U.S. military base overseas, if they immigrate to the United States, or if they are born on American soil to non-U.S. citizens.
Step-by-step explanation:
In the scenario where a person is born on a U.S. military base overseas, they may gain U.S. citizenship by naturalization. This is because being born on a U.S. military base is considered being born on U.S. soil. The Fourteenth Amendment to the U.S. Constitution grants citizenship to anyone born in the United States or its territories, including military bases.In the scenario where a person with no ties to the U.S. immigrates to the United States, they may also gain U.S. citizenship by naturalization. This would involve going through the naturalization process, which includes meeting eligibility criteria such as being a permanent resident, having good moral character, and passing English and civics tests.
In the scenario where two non-U.S. citizens have a child on American soil, the child may be granted U.S. citizenship. This is known as birthright citizenship or jus soli, where anyone born in the United States, regardless of their parents' citizenship, is automatically a U.S. citizen.