Question

The United States intervened in Vietnam to

create a dependent colony out of South Vietnam that applied for U.S. statehood after a certain amount of time
preserve an independent and democratic South Vietnam, but it withdrew and the country united under communism
help the independent South Vietnam take control of its northern neighbor, and the country united under a representative democracy
force the dependent South Vietnam to accept U.S. rule until it could establish independence from colonial rule and become an independent country