1-C. Hannibal has kept the neighborhood where Twain grew up just as it was in the 1840s.Hannibal has kept the neighborhood where Twain grew up just as it was in the 1840s.
2-C. Hannibal is where Mark Twain grew up and it's the town he used in his story.Hannibal is where Mark Twain grew up and it's the town he used in his story.