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.

Which element begins the fourth group of the periodic table?
Titanium

In what movie did the song white christmas make its debut?
Holiday Inn

Who is the youngest us president elected to the office?

John F Kennedy