How can you break down any barriers of communication when mentoring someone? give an example.

Try things like drawing or listening to music to see if you relate in interests. Ask them what their favorite hobby is and talk about it! 
Ask them what their favorite item is and talk about why they like it or why it is important to them? 
Maybe ask them what they like to talk about (cars, celebrities, animals etc) and have a normal conversation and then once they enjoy chatting, then move on to the more "mentor-y" stuff :)

The first step is finding something you are both interested in or can relate to to make them feel comfortable

Iwould say d) signed unknown street singers who brought original songs to record.