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?

The answer is c :)

hope this helps

the answer is   b suffix addition

the correct answer is option d. none of these. it is noted that options a, b, and c share the same content.

despite the valid answer provided at the last sentence of each of the options, a question/answer format shouldn't include humourous themed responses such as "you bet your thermal pj's we do." - unless of course, the answer is carried out in an informal environment. this could be replaced with a simple "yes" or "it is necessary".

the question should be re-phrased to a more appropiate syntaxis. instead of "do we need the greenhouse effect? ", it should be written as "is the greenhouse effect necessary? " in order to give it a general scope, instead of limiting the answer to the needs of "we" the humans.