What does the passage justifies? But when a long train of abuses and usurpations ... it is their right, it is their duty, to throw off such Government, and to provide new Guards for their future security.

The correct answer for this question is this: "The passage justifies security within ourselves and the nation. If the government cannot provide such security that the people and the country needs, then it's better to throw off such government. National security is a must.