Since 1984, the most common correct answer on Jeopardy! has been "What is China?" In fact, that has been the right response 216 response over the past three decades — according to this incredibly detailed look at every Jeopardy! match between 1984 and 2012 by Patrick Tullao:
The graphic (the version on Tableau is interactive) is a pretty good cheat sheet if you happen to be studying for an upcoming Jeopardy! appearance: focus on science, literature, history, and geography. But more than anything, Jeopardy! clue writers love their wordplay: The most common category is "Before and After" — which requires you to know two pieces of information to get the right answer. ("This colorful North American bird is also a central figure in F. Scott Fitzgerald's most famous novel." "What is Blue Jay Gatsby?")
Tullao's graphic is based on nearly 217,000 questions — meaning that even if you diligently study China, it's still only been the answer one out of 100,000 times. You could study literature and end up facing categories about Broadway musicals and actresses named Kate. And "Before and After" has been on the decline lately. In 2011, the most common category was "Word Origins," which has been the source of Final Jeopardy questions most often.'
Correction: Jay Gatsby is not the narrator of The Great Gatsby, and if you say he is, you will not win Jeopardy! or pass high school English.