What is the relationship between Realogy and Century 21 Real Estate 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.

Housing Industry Town Halls and Educational Break Out Groups: Carmen Mercado, national director, strategic growth markets for Realogy Franchise Group and a NAHREP Past President; Juan Martinez, broker/owner, CENTURY 21 Martinez & Associates; Charlie Young, president & CEO, ERA Real Estate; Top Producer Panelists: Erika Villegas, ERA Mi Casa Real Estate, Chicago; and, Alicia Trevino, CENTURY 21 Alicia Trevino Realtors Uptown, Dallas; Oralia Herrera, CENTURY 21 T.K., Broker/Owner; Frank Malpica, director of products and platforms for ERA Real Estate; Sergio Soto, ERA Mi Casa Realtors; Joe Castillo, ERA Mi Casa Realtors; JJ Lopez, CENTURY 21 Realogy Masters; and, Alex Chapparo, director of multicultural and growth markets for Century 21 Real Estate LLC.

Answer: subsidiary