A) Nail
You use thread with a needle and a nail with a hammer
Our world would be different because without the printing press we would have no books, so school would be different and probably more difficult. Without the printing press we never would have printed bibles so church and any religious studies would be different (and probably more difficult) AND of course we would have no newspapers so there would be less advertising, and nothing to read on Sunday morning.
To be successful, you need to have a good mindset about your goals. Make sure you never give up and work the hardest you can. Even if it means having hours and hours of labor and minimum hours of rest. Everyone wants to be successful, but not everyone wants to work for it.