The correct answer is:
C. Committing large amounts of American troops to the fight and massive bombing
Lyndon B. Johnson's strategy during Vietnam War was basically sending more troops to reinforce due to the devastating loss the attack by the Vietcong agains the US left. He commited a several amount of troops to Vietnam in 1968. He wanted to increase the chances of American success in stopping the spread of communism to South Vietnam.
I think great granddaughter.
Several of these figures were anti-capitalist, as well as anti-religion. They were also revolutionaries, not advocates of a rigid social system so the correct answer is (4) achieving change through revolution.
Truman Doctrine
In 1947, Truman pledged that the US would aid any nation in resisting the growing threat of communism to help prevent its spread.