Utilize the input text as a context reference, choose the right relationship between Realogy and Century 21 Real Estate from the options. Options: 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