Which is the best example of evidence? a) first of all, if someone says your dream is impossible, they're wrong. b) you can't prove that something is impossible-all you know is that [ it] hasn't been done yet. c) people said no one could scale mount everest, but in 1953, sir edmund hilary and tenzing norgay gazed down upon the world from its summit. d) if we can send three men a quarter of a million miles away and bring them home safely, is there any great task we cannot accomplish?