Take context from the input text and decide on the accurate relationship between 'Rubicon Project' and 'LOS ANGELES' from the options provided.
Options: creator, headquarters location, publisher, employer

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
headquarters location