It would be the Scientific method.<span />
He is saying that you need to look at Berlin if you want to see why communism has failed and the spirit of freedom has prevailed under very difficult circumstances.
D is so horribly wrong that I have to make note of it.
The best answer is C. Thanks for posting this. I've never read this speech by Kennedy and it is a landmark of poly sci. Everyone in America should read it.
its B.metaphor a figure of speech in which a word or phrase is applied to an object or action to which it is not literally applicable.