C would be the best, because it is the one that starts a discussion about the art and not just the museum. It also does not sound aggressive about liking the art himself. Hope this helps!
Essentially the difference would be that when you talk to your friend, you would use an informal register: you would for example directly say what you need "hey, pass me that thing" while when you write a letter to Unisa you would use polite language and formal register, for example you would say" I would be very happy to receive from you the following..." -even thought the two sentences express the same thing!
He's still relevant because he was the voice of an era. His plays have a timeless quality about them that help them resonate with people of every time period. We study shakespeare because he is one of the most well known playwrights and thus, to not study his work would be a severe oversight.