What was an effect of us troops leaving vietnam in 1973? vietnam’s economy grew. vietnam became communist. vietnamization failed. vietnam repaid the united states. pls answer !

The correct answer is the second: Vietnam became communist. After the peace agreement negotiated by the Nixon administration in 1973, the U.S. agreed to withdraw its troops in exchange for a prompt ceasefire, and North Vietnam agreed to recognize the government of South Vietnam. However, the ceasefire did not come into being, and South Vietnam eventually fell to North Vietnamese forces in 1975. A year later, North and South Vietnam merged to create the Socialist Republic of Vietnam under a communist government.

Since the army of South Vietnam was not capable of guaranteeing their safety against North Vietnam, it is also possible to say that Nixon's Vietnamization strategy failed.  

Explanation:

The US had been supporting South Vietnam against the communist North Vietnam.  Ultimately, US President Richard Nixon proposed drawing down US involvement in the war and seeking "peace with honor," as he put it.  (This was after he had proposed "Vietnamization," a policy which had failed prior to 1973.)  

Once the US forces withdrew (after a long, unsuccessful struggle), it was too late for the South Vietnamese to stave off the victory of the North Vietnamese and Viet Cong forces.  The US withdrew its forces from Vietnam in 1973.  By 1975, Saigon, the capital of South Vietnam, fell to the North Vietnamese communist forces.  South Vietnam unconditionally surrendered to North Vietnam on April 30, 1975.  All of Vietnam became united under communist control.

answer should be c..