Given an trivia question precisely answer the question with a word/phrase/name. External resources such as Wikipedia could be used to obtain the facts.

Which John Legend song knocked Pharell Willams completely off the No.1 spot on the US Billboard?
all of me

The term paparazzi' is derived from the name of a character in which film by Federico Fellini?
la dolce vita

Who did James Earl Ray shoot in Memphis in April 1968?

martin luther king, jr.