Pick one category for the following text. The options are - company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work. Stefan Muller (footballer born 1988) - Stefan Muller (born 9 November 1988 in Karlsruhe) is a German footballer who plays for KSV Hessen Kassel.Muller made his debut for Karlsruher SC on 3 April 2010 in a 11 away draw against 1. FC Union Berlin after coming off the bench to replace Anton Fink in the 89th minute.
A:
Athlete