The version of the underlined text that best matches the tone and purpose of the passage is: operates the world's largest.
The tone of this passage focuses on the role of the United States as a host to refugees from many parts of the world.
The figures mentioned and the different cities listed where refugees stem from shows that the number of refugees that the United States welcomes into its fold is much.
So, the phrases, "the world's most amazing program" and "operates the largest," contribute to the tone and purpose of the passage.
Learn more about tone here:
https://brainly.com/question/12176973