Jonas Hummels (born 5 August 1990) is a German retired footballer who played as a central defender for SpVgg Unterhaching. He is the younger brother of German international Mats Hummels, and the son of Hermann Hummels, a former footballer and manager. Using only the above description and what you know about the world, "Jonas Hummels was a former footballer, who also had a father who was a footballer." is definitely correct, incorrect, or inconclusive? 