Valerie Singleton OBE (born 9 April 1937) is an English television and radio presenter best known as a presenter of the popular children's series "Blue Peter" but who went on to present the BBC Radio 4 "PM" programme for ten years as well as a series of radio and television programmes on financial and business issues.
Mark Durden-Smith (born 1 October 1968 in Soho, London) is an English television presenter best known for presenting ITV shows such as "" and "This Morning Summer" and Sky 1 shows such as "The Match" and "Double or Nothing".
It's a Mystery was a networked Children's ITV programme which ran for five series from 12 September 1996 to 9 May 2002.
 It was produced by The Media Merchants Television Company Ltd and Meridian Broadcasting Ltd.
 In Series five, the show was retitled as "Mystery" and featured different presenters.
 It was a magazine show featuring unusual stories including about UFOs, ghosts and other difficult to explain happenings, some of which were solve others which remained unexplained.
Neil Buchanan (born 11 October 1961) is an English television presenter and musician best known for his work on the CITV programme "Art Attack", a television programme that he co-created and presented during its original run from 1990 to 2007.
 He also presented "Finders Keepers" (1991–1996) and "It's a Mystery" (1996–2000), and produced and appeared in "ZZZap!
" as Smart Arty (1993–1998).
Zzzap (rendered ZZZap!)
 was a British children's television comedy programme.
 The concept of the show is a giant 18 ft comic that has been brought to life.
 The show was broadcast on ITV from 8 January 1993 until 21 September 2001 and was produced for ten series by The Media Merchants and Meridian Broadcasting.
Lorna Maseko (born July 3, 1983) is a South African ballet dancer, Choreographer and Television presenter best known as a presenter on the SABC3 lifestyle magazine programme Top Billing.
Thomas John Gillespie "Tom" Heap (born 6 January 1966) is the Rural Affairs Correspondent of BBC News, and a United Kingdom television and radio reporter and presenter best known for his contributions to the BBC One programme "Countryfile", the same channel's "Panorama" programme, and the BBC Radio 4 programme "Costing the Earth".
 Since February 2012, he has also been Director and media presenter of the media company Checked Shirt TV Limited.
Pam Rhodes (born 22 September 1950) is an English television presenter best known for presenting the BBC television long-running religious series "Songs of Praise".
Lorne Spicer (born 16 September 1965 in Upminster, Essex) is an English television presenter best known for presenting reality shows on the BBC's current daytime output.
The Media Merchants Television Company ltd. (also known as The Media Merchants Production or simply The Media Merchants) was an independent television production company specialising in children's programmes, run by Neil Buchanan and Tim Edmunds.

Question: The Media Merchants were run by an English television presenter best known for work on what programme?
Answer: Art Attack