TASK DEFINITION: In this task, you're given an open-domain question. Your task is to provide an answer to the given question. There is only one unique answer for each question. Your answer should be short, and refer to an entity, date, number, etc. Do not put your answer in the context of a sentence.
PROBLEM: Who played zuzu in it's a wonderful life?

SOLUTION: Karolyn Grimes

PROBLEM: Who presides over any impeachment trial of the president of the united states?

SOLUTION: Chief Justice of the United States

PROBLEM: Explain what the british understood by the term terra nullius?

SOLUTION:
territory may be acquired by a state's occupation of it