Question: Alex Mahon will succeed the executive who founded what creative agency?

Context paragraphs:
DCF Advertising: DCF Advertising (corporate name, Mind4, Inc.) is a creative agency based in Midtown Manhattan, New York City.  The agency specializes in public health and social marketing.  The agency was founded in March 2000 by James DeAngelo.  Partner John Fortune joined the firm in 2003.

Sang Bleu: Sang Bleu (] ) is an independent, multi-disciplinary media platform and creative agency encompassing "Sang Bleu" magazine, a publication centred around contemporary art, culture, fashion, fine art, performance art, literature, sociology, kink and tattooing; SangBleu, a typeface under the type design company Swiss Typeface and a creative agency called Sang Bleu.  Sang Bleu was initiated in 2006 in London, UK, by Maxime Plescia-Büchi, its Swiss creative director, who currently runs it with his wife Hope Plescia-Büchi.  Büchi performs as a tattoo artist at Sang Bleu London together with a dozen other tattoo artists and temporary resident artists.  Sang Bleu is notable for its publications, its collaboration with Swiss luxury watchmaker Hublot and its work on celebrities like Kanye West and FKA Twigs.  Sang Bleu is also known for creating logos and corporate typefaces for Balenciaga, Rick Owens, CSS Bard Hessel Museum, the City of Stockholm, Esquire magazine and Vogue.  It has held events at department stores including Selfridges, the London Edition Hotel and Imperial Art Studios in Downtown Los Angeles.  In May 2016, the first international Sang Bleu studio opened in Zürich, Switzerland.

Alex Mahon: Alexandra Rose Mahon (born October 1973) is a British businesswoman, the chief executive-designate of Channel 4, who will succeed David Abraham, when he leaves in October or November 2017.

Genevieve Clay: Genevieve Clay-Smith (born 1988) is an Australian-born writer and film director.  She grew up in Newcastle and attended the Hunter School of Performing Arts in Broadmeadow.  She is the winner of the 2009 Tropfest short film festival as well as a number of other Australian film festivals.  She is an advocate for social justice and inclusion for people living with a disability.  She is executive director of the not-for-profit organisation Bus Stop Films.  Bus Stop Films is dedicated to helping people with a disability and people from other marginalised communities learn about and be involved in the film industry.  She is also the co-founder of creative agency, Taste Creative.

Advertising agency: An advertising agency, often referred to as a creative agency, is a business dedicated to creating, planning, and handling advertising and sometimes other forms of promotion and marketing for its clients.  An ad agency is generally independent from the client; it may be an internal department or agency that provides an outside point of view to the effort of selling the client's products or services, or an outside firm.  An agency can also handle overall marketing and branding strategies promotions for its clients, which may include sales as well.

Loretta Chen: Loretta Chen is a Singaporean theatre director, television presenter, radio personality, author and creative executive.  She was the Group Business Development & Creative Director of The Activation Group, a regional creative agency and production house.  She is currently based in Honolulu but is Visiting Professor at the School of Leadership and Organisational Studies at the University of Southern Maine.

Next Fifteen Communications: Next Fifteen Communications Group Plc is a digital marketing communications and public relations group.  It has more than 1,350 employees working across 32 offices in 14 countries.  It owns four independent public relations brands: Text 100 and The OutCast Agency focus on technology, business and corporate communications; Lexis and M Booth both specialise in consumer communications.  The Group also owns a global marketing services agency (Bite), research businesses (MIG Global - including Morar HPI & Viga), a policy communications and corporate advocacy business (Vrge Strategies), a strategic investor relations consultancy (Blueshirt Group), a creative agency (ODD London), a technical marketing communications agency (Publitek), a B2B marketing agency (Twogether) and a digital agency (Beyond).

Giant Step: Giant Step is a media, events and marketing company headquartered in New York City.  The company formerly released music through its record label, Giant Step Records.  Giant Step is divided into two entities - the Giant Step brand, which promotes music and the creative agency, Giant Step Marketing, which provides marketing services to corporate brands.  The Giant Step brand aims to introduce quality music and talent to its community.  The slogan of the creative agency, Giant Step Marketing is that of, "Elevating brands through music and culture."

Staple Design: Staple Design is a visual communications agency based in New York City and founded in 1997.  It has three main divisions: a clothing collection, a creative agency and a retail store.  Staple is a full lifestyle menswear collection and is distributed globally.  Staple mixes street-minded sensibilities with mature sophisticated nods to high-end fashion.  Staple Design Studio is a creative consulting firm that has worked with many brands including Nike, Microsoft, Sony, Lotus, Timberland, New Balance, LVMH and others.  Staple Design also owns and operates Reed Space in the Lower East Side of New York City.  Reed Space is often regarded as one of the world’s best and most innovative boutiques.  It also features an art gallery, which has hosted some of our generation’s most celebrated artists.

David Abraham (executive): David Abraham (born August 1963) is a British media executive, who is the chief executive of Channel 4 Television Corporation – the UK’s self-funded public service broadcaster.  After an early career in advertising that led in 1997 to the foundation of the creative agency St. Luke’s, Abraham went on to senior creative roles at Discovery Communications in the UK and the US before becoming CEO of UKTV in 2007.

Supporting paragraphs: Alex Mahon David Abraham (executive)
Answer: St. Luke’s