The correct answer is C) the fighting continued until Vietnam became united under a Communist government.
After the United States withdrew from Vietnam in 1973, the fighting continued until Vietnam became united under a Communist government.
On January 23, 1973, US President Nixon announced that an agreement has been reached to end the war. Four days later, the US, the Viet Cong, North, and South Vietnam signed the Paris Peace Accords. The US agreed to stop any military action and withdraw the rest of the troops from Vietnam in 60 days. North Vietnam accepted to stop hostilities. Vietnam continued to be one country under two governments.