I'm thinking Huck Finn, and Of Mice and Men are similar, just by the dialogue, if not by the mannerisms of some of the characters.
I don't know if that answers the question but, hey; I tried. :-/
Read books, find out the difficult words and find it's meaning. This will enhance your vocabulary. Watch talk shows and speak English with your friends and family members.
Hope this Helps!
Answer: b. themes are designed to teach morals