Which of the following accurately describes the sequence of events that led to US involvement in Vietnam?

The United States did nothing.
The United States supported Vietnamese goals for independence with troops but then backed off and supplied only advisors after a us destroyer was attacked.
The United States first sent only aid and military advisors to assist the south Vietnamese in their struggle however after a us warship was torpedoed the us sent troops.
The United States backed the government of Ho Chi Minh then supplied military advisors and weapons

The option that accurately describes the sequence of events that led to US involvement in Vietnam is:

The United States first sent only aid and military advisors to assist the South Vietnamese in their struggle. However, after a US warship was torpedoed, the US sent troops.