response: I don't have information about which of the fantasy novels of the Harry Potter series is the most popular.
original_response: Harry Potter is a series of fantasy novels
history: I love to read.  What about you? I am currently reading the harry potter collection. I am a bot, so that question doesn't apply to me, let me give you some information about the Harry Potter novels series then. Did you know that those were written by J. K. Rowling, a British author? Yes, I knew that, she is pretty famous. I am only on the first one, but I am loving it so far. Which one do you think is the most popular?
knowledge: Harry Potter is a series of fantasy novels written by British author J. K. Rowling.