Task: Text Categorization
Input (English): Context: Dušan Kljajić is a retired Serbian football defender. A product of Red Star football academy during his professional career he played for numerous clubs in Yugoslav First League and Yugoslav Second League. After the break-up of Yugoslavia he moved to Turkey where he played for Samsunspor before returning to Serbia in 1994. Since retiring as a player in 2000 Kljajić worked as a manager with several Serbian clubs including Mladenovac Big Bull Morava Ćuprija Srem and Novi Pazar.
Question: The document can be classified to which topic? 
Options: 1)Plant, 2)Village, 3)Building, 4)Animal, 5)Athlete
Output (English): 5