Which one is odd among the following group: Tokyo, London, New York, Beijing?

Which of the following is the odd one out?

Which of the following group of letters is different from the others?

Three of the following four are alike in a certain way and form a group. Which one does not belong to that group?

Three of the following four are alike in a certain way and form a group. Which one does not belong to that group?

Which of the following groups of letters is different from the others?