What is the relationship between Chicago Tribune and Chicago in the context of the input sentence. Choose an answer from: product/material produced; manufacturer; distributed by; industry; position held; original broadcaster; owned by; founded by; distribution format; headquarters location; stock exchange; currency; parent organization; chief executive officer; director/manager; owner of; operator; member of; employer; chairperson; platform; subsidiary; legal form; publisher; developer; brand; business division; location of formation; creator.

Chicago Mayor Rahm Emanuel is preparing to press for a property-tax increase of about $500 million to shore up police and firefighter pensions that threaten the city’s solvency, the Chicago Tribune reported.

Answer: headquarters_location