What is the relationship between Rubicon Project and LOS ANGELES 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.

LOS ANGELES & LONDON--(BUSINESSWIRE)-- Launch of Argentina and Hungary Advertising Co-Ops Expands Rubicon Project Leadership Role as The Exclusive Publisher Co-operative Marketplace Serving More Than 290 Premium Publishers Globally

Answer: headquarters_location