What did american leaders during the cold war think about the political situation in vietnam?

a. they thought that if communist leaders took control of vietnam, all of southeast asia would ultimately ally with the soviet union.

b. they thought that if they supported the communist cause in vietnam, it would improve relations between the soviet union and the west.

c. they thought that if the french colonialists succeeded in vietnam, other countries would set up colonies in the region as well.

d. they thought that if communists won the vietnamese election, they would immediately attack the united states.