user: Question: Who is the head coach of the team, whose shirt sponsor is Karstadt Quelle Versicherungen?
Columns: ['Team', 'Head coach', 'Team captain', 'Kitmaker', 'Shirt sponsor']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Alemannia Aachen', 'Jürgen Seeberger', 'Reiner Plaßhenrich', 'Jako', 'Aachen Münchener']
SQL:

assistant: SELECT "Head coach" FROM "Table" WHERE "Shirt sponsor" = 'Karstadt Quelle Versicherungen';