The correct answer is A. "Insure domestic Tranquility"
Step-by-step explanation
On September 11, 2001, a historic event occurred in the United States in which two commercial aircraft were hijacked by religious extremist terrorists and crashed into the World Trade Center buildings better known as the Twin Towers. Hundreds of people were killed and many others were psychologically affected. This fact caused worldwide rejection and allowed many nations led by the United States to begin to strive to guarantee national security and combat terrorism. In this context, security measures were increased in massive places, to prevent a similar event from happening again and that the domestic population of the United States feels safe with the measures taken by the government. Therefore, the correct answer is A. "Insure domestic tranquility"