Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.
Q: Context: In a brief period between World War I and World War II the Kingdom of Yugoslavia, successor to the Kingdom of Serbia, formed a ''Small Entente'' loose union between Czechoslovakia, Romania and Yugoslavia.
Question: Which replaced the Kingdom of Serbia?
A:
kingdom of yugoslavia