How does Kennedy use the juxtaposition to assure his audience "that the torch has been passed to a new generation of Americans--born in this century, tempted by war, disciplined by a hard and bitter peace"; further pointing out that "we observe today not a victory of party, but a celebration of freedom--symbolizing an end, as well as a beginning--signifying renewal, as well as change"?

He uses ethos to make the people of America believe what he says.

Explanation:

Kennedy said the rights cannot come from the hands of a man but it is in the generoisity of the state. he said if a free society cannot help manypoor  people, then it cannot save the few rich people. 'The torch has been passed' makes the people patriotic and gives assurance to the people to trust him. He also makes people have faith in the decision he takes.He creates a sense of feeling which makes people think what will he do as a President.

The answer would be a.