It is an absolutely true statement that Eisenhower, Kennedy and Johnson all approved of the United States backing the South Vietnamese in their Civil war. The correct option among the two options that are given in the question is the first option. All of them backed this idea for stopping the spreading of communism.
Eisenhower kennedy and Johnson approve the backing of the south Vietnamese because their opposition was controlled by communist group which they believe was really dangerous and could serve as potential thread for united states in the future
