How did the Gulf of Tonkin incident contribute to the escalation of tensions in Vietnam? It caused the United States to fear for the safety of its troops.
o It was one of the deadliest incidents of the Vietnam conflict.
o It made the North Vietnamese upset about being falsely accused.
It prevented U. S. ships from returning to South Vietnam.

The third explanation.

Explanation:

Subsequently proved to be based on false claims, the Gulf of Tonkin incident led to a rapid and significant escalation of US involvement in Vietnam. Thus it is understandable that the North Vietnamese were upset about being falsely accused.

b). (sounds as the best answer)

answer: secession

secession, as it applies to the outbreak of the american civil war, comprises the series of events that began on december 20, 1860, and extended through june 8 of the next year when eleven states in the lower and upper south severed their ties with the union. the first seven seceding states of the lower south set up a provisional government at montgomery, alabama. after hostilities began at fort sumter in charleston harbor on april 12, 1861, the border states of virginia, arkansas, tennessee, and north carolina joined the new government, which then moved its capital to richmond, virginia. the union was thus divided approximately on geographic lines. twenty-one northern and border states retained the style and title of the united states, while the eleven slave states adopted the nomenclature of the confederate states of america.

explanation: