Question: Where is the headquarter of an American restaurant holding company who's chairman and chief executive officer was Jon L. Luther?
Sentence (from "Jon C. Madonna"): Subsequent to his retirement from KPMG in 1996, Madonna served as vice chairman of Travelers Group, Inc. from 1997 to 1998, and president and chief executive officer of Carlson Wagonlit Corporate Travel, Inc. from 1999 to 2000.
Relevant evidence: No