Question: Simmons Bedding Company is the sister company of the mattress manufacturer based in what city?

Context paragraphs:
Mattress Giant: Mattress Giant Corporation was an American retailing company and mattress store chain founded in 1986 in Miami, Florida.  The company was based in Addison, Texas.  In 2012 it was announced Mattress Firm would acquire all Mattress Giant locations in the U.S in a $47 million deal, virtually all Mattress Giant locations will convert to Mattress Firm.  Some stores were converted to Sleepy's which were later converted to Mattress Firm.  The deal closed in July 2012 and it effectively ended Mattress Giant's presence as a bedding retailer.  The website was operated through December 2012; and it delivered mattress related products to houses.

Fullpower Technologies: Fullpower is a privately held intellectual property and technology licensing company based in Santa Cruz, California.  Fullpower's cloud-based IoT and wearable solutions are used in products from Nike, Movado, Simmons Bedding Company, Serta and others to track activity and monitor sleep.

Simmons Bedding Company: The Simmons Bedding Company is an American major manufacturer of mattresses and related bedding products, based in Atlanta, Georgia.  The company was founded in 1870, and is one of the oldest companies of its kind in the United States.  Simmons' flagship brand is "Beautyrest".  In addition to operating 18 manufacturing facilities in the United States and Puerto Rico, the company licenses its products internationally.  According to a Simmons press release, net sales for 2005 were $855 million, and its revenue was $1.13 billion in 2007 and $1.228 billion in 2013.  As of 2011, Simmons ranked in third place among U.S. mattress manufacturers, with a 15.7 percent market share.  In 2012, Simmons and its sister company Serta International were acquired by American private equity company Advent International.

Martin Williams Advertising: Martin Williams Advertising, Inc. is an advertising agency, based in Minneapolis, Minnesota.  Since 1998, Martin Williams has been part of the Omnicom Group.  Clients include Payless ShoeSource, Raymond James, Syngenta, Cargill, Marvin Windows, Simmons Bedding Company, and P.F. Chang.

Sleeper Mattresses and Bedding Company: Sleeper Mattresses and Bedding Company is one of the top 100 companies in the Middle East.  Sleeper (a Branch of Al-Rajhi Industrial Group) was established in 1980 and is located in the industrial area of Al-Kharj Road, Riyadh, Kingdom of Saudi Arabia (K.S.A).  Sleeper Mattress and Bedding Company is the member of International Sleep Products Association (ISPA) and is authorized by I.S.O-9001-2000.  Certificate No. 545178

Serta (company): Serta is an American company based in Hoffman Estates, Illinois that specializes in developing and manufacturing mattresses.  It was founded in 1931 in Illinois as Sleeper, Inc. by 13 mattress manufacturers who licensed the Serta name; subsequently eight independent licensees acting like a cooperative owned the company.  Afterwards, it was controlled and operated as Serta International by its largest licensee, National Bedding Company, (which ultimately held 27 of the 34 U.S. Serta manufacturing licenses).  In 2005, two private equity groups teamed up to purchase National Bedding Co.--The Ares Corporate Opportunities Fund, the Los Angeles-based private equity fund of Ares Management; and Teachers’ Private Capital, the private equity arm of the Ontario (Canada) Teachers’ Pension Plan.  The American company Serta International is a subsidiary of the American company Serta Simmons Holdings LLC.

United Furniture Workers of America: The United Furniture Workers of America (UFWA) was a 20th-century American labor union, founded as a breakaway from the Upholsterers International Union of North America by a group of labor activists, who included Emil Costello (a Wisconsin state legislator and president of the UIU local at Simmons Bedding Company's original factory in Kenosha, Wisconsin) in 1937.  The UFWA advocated industrial unionism and affiliated with the Congress of Industrial Organizations (which had formed in 1936).

Protect-A-Bed: Protect-A-Bed® is a manufacturer and distributor of protective bedding products(including mattress protectors and encasements) that help protect against bed bugs, dust and allergens. Protect-A-Bed products are available in 45 countries.  Protect-A-Bed supplies mattress and pillow protectors to 7 of the 11 top bedding specialists in the United States, several of the top 100 U.S. furniture chains, and all the major distributors in the pest control industry and hospitality industry.  Protect-A-Bed products are also sold by national retailers including J.C. Penney, Target, Kohl’s, Costco, and Sears.  The company currently has in excess of 7,000 furniture and bedding store clients in the United States as well as serving pest control and hospitality markets with bedding protection products.  Protect-A-Bed is the developer of Miracle Membrane®, a proprietary membrane, which is waterproof and protects against liquids, as well as the patented BugLock® with SecureSeal® and three-sided zipper system for encasements.  Protect-A-Bed products are listed as Class 1 Medical Devices with the Food and Drug Administration, and have received the Good Housekeeping Seal.

Dale Carlsen: Dale R. Carlsen founded The Sleep Train Mattress Center in 1985, and has guided the company to become the largest retailer of mattresses on the West Coast, and one of the top three in the United States.  In 2002, Dale purchased 54 of Mattress Discounters' stores in California during that company's bankruptcy—more than doubling Sleep Train's size.  In August 2006, Dale purchased Sleep Country USA from Simmons Bedding in a move to re-enter the northwestern market.

Chittenden &amp; Eastman Company: Chittenden & Eastman Company (established in 1866) is an American handcrafting mattress manufacturer originally based in Burlington, Iowa.  The company has thirty factories around the world and is currently headquartered in North Brunswick, New Jersey.  Chittenden & Eastman's intellectual property has since been purchased by Mattress Development Company of Delaware which reintroduced the Eastman House brand into the marketplace.  The company is active with over 30 factories and licensees worldwide.

Supporting paragraphs: Simmons Bedding Company Serta (company)
Answer: Hoffman Estates, Illinois