Question: Marc Herring has had, as a client, the wireless and electronics chain that was founded in which year?

Context paragraphs:
Crazy Eddie: Crazy Eddie was a consumer electronics chain in the Northeastern United States- previously called ERS Electronics (ERS stood for Eddie, Rose and Sam; Rose and Sam were Eddie’s parents).  It was started in 1971 in Brooklyn, New York, by businessmen Eddie and Sam M. Antar.  The chain rose to prominence throughout the Tri-State Region as much for its prices as for its memorable radio and television commercials, featuring a frenetic, "crazy" character played by radio DJ Jerry Carroll (who copied most of his shtick from early TV-commercial pioneer, used car and electronics salesman Earl "Madman" Muntz).  At its peak, Crazy Eddie had 43 stores in four states, and reported more than $300 million in sales.

RadioShack: RadioShack is an American chain of wireless and electronics stores, founded in 1921 and since 2017 has approximately 28 remaining corporate locations, which are owned by General Wireless Operations, Inc., who are leasing the name from Kensington Capital Holdings.  In addition to the corporate locations, as of September 2017 RadioShack operates as an online website and the name is licensed to approximately 425 independently owned franchise stores.

Global Tower Partners: Global Tower Partners (GTP), owned by American Tower Corporation and previously based in Boca Raton, Florida, was the largest privately owned tower operator in the U.S. and the fourth largest independent operator in this sector.  GTP owned, managed, or held master leases for more than 16,000 wireless sites and over 40,000 miles of railroad rights of way throughout the U.S. GTP leased space on towers and rooftops to leading wireless communications providers including AT&T Wireless, Verizon Wireless, Sprint, T-Mobile, US Cellular, Metro PCS, and Leap Wireless.  GTP was founded in 2002 and began operations in October 2003.  Marc Ganzi, the company's Chief Executive Officer, was the sole founder.

Helmut Niedermeyer: Helmut Niedermeyer (28 February 1926 – 3 February 2014) was an Austrian businessman and entrepreneur.  He founded Niedermeyer, which was once the largest consumer electronics chain in Austria.

Marc Herring: Marc Herring is a Multimedia Artist and the CEO-Executive Producer of Herring Media Group, an international communications, design and production agency.  Marc's clients have included: Live Earth / Washington DC with Al Gore, Yahoo! Inc. , The Wadsworth Atheneum Museum of Art, SFMOMA, The Smithsonian Institution, ILM / Lucas Digital Ltd., Lexus, RadioShack, Procter & Gamble and most major broadcast networks and international advertising agencies.  His work has been extensively covered by the international news media and presented in museums and universities throughout the world.

Oscar Farinetti: Natale Farinetti, known as Oscar (] ; Alba, 24 September 1954), is an Italian businessman and investor.  Farinetti is the current owner of the high-end Italian food mall chain Eataly and founder of the consumer electronics chain UniEuro.

Holiday Film Festival: Holiday Film Festival was a Thanksgiving Day science fiction film series, aired annually from 1976 to 1985 on WOR-TV Channel 9 in the Tri-State Region.  For most of these broadcasts the two sponsors were a local electronics chain, "Crazy Eddies", and a toy store "Play World".  Play World's level of sponsorship was such that, for at least the 1979 line-up, in addition to the many ads they ran for the store itself, they also sponsored a "TV crossword game" during commercial breaks, in which viewers could win a shopping spree or gift cards.

Luskin's: Luskin's was an electronics chain based in Baltimore, Maryland that began in 1948 and closed down in October 1996.

Electronics World: Electronics World (which may claim a connection with Wireless World, founded in 1913, and in September 1984 renamed Electronics & Wireless World) is a technical magazine in electronics and RF engineering aimed at professional design engineers.  It is produced monthly in print and digital formats.

Witmark: Witmark was a catalog showroom and jewelry/electronics chain that operated in West Michigan from 1969 to 1997.  The chain was founded by Paul Leven.

Supporting paragraphs: Marc Herring RadioShack
Answer: 1921