Question: Who was the "The X Factor" runner up to the winner whose single, "Impossible", has gone on to sell over 1.4 million copies in the UK?
Sentence (from "James Arthur"): Since then, it has gone on to sell over 1.4 million copies in the UK, making it the most successful winner's single in the show's history and has sold over 2.5 million copies worldwide.
Relevant evidence: Yes