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 presides over any impeachment trial of the president of the united states?

SOLUTION: Chief Justice of the United States

PROBLEM: When was the pledge of allegiance started in schools?

SOLUTION: October 12, 1892

PROBLEM: Who was the first head of the department of homeland security?

SOLUTION:
Thomas Joseph Ridge