Question: Who co-produced the single with which Coldplay became popular?

Context paragraphs:
Paradise (Coldplay song): "Paradise" is a song by the British rock band Coldplay.  The song was released on 12 September 2011 as the second single from their fifth album, "Mylo Xyloto".  The song received its radio debut at 7:50 a.m. on "The Chris Moyles Show" (BBC Radio 1) on 12 September 2011.  According to Coldplay's official website, the single was not initially chart eligible in the United Kingdom, because it was available on iTunes as an "instant grat" (immediate download) when pre-ordering the album.  Following the release of the album on 30 October 2011, the song became chart eligible in the UK and entered the UK Singles Chart at number 14, before taking the number 1 spot on its tenth week, becoming the band's second number-one single after "Viva la Vida" in 2008.  The song was met with positive reviews, and was the best selling rock song of 2011 in the United Kingdom, selling 410,000 copies.

Punk in Sweden: Punk rock and hardcore punk have created a punk subculture in Sweden since punk music became popular in the 1970s.  The most famous Swedish punk band was Ebba Grön, followed by KSMB; other notable bands were Asta Kask, Grisen Skriker, Kriminella Gitarrer, The Pain and Göteborg Sound.  In the 1980s hardcore punk, kängpunk and crust punk became popular in Sweden.  The two perhaps most influential bands are Mob 47 and Anti Cimex, whose music has also inspired many foreign bands.  Some other examples of influential bands are Moderat Likvidation, Black Uniforms, Totalitär and Avskum.  Together with the early American hardcore bands and the British band Discharge, the Swedish punk scene since the early 1990s consisted almost exclusively of "tribute bands" to the above.  In the 1990s the crust punk was still going strong with bands like Driller Killer, Skitsystem, Wolfbrigade, and Disfear.

Goreti Venkanna: Goreti Venkanna (born 1963) is a popular Indian poet and folk singer.  He became popular after his song "Palle Kanneru Peduthundo" in Khubasum Telugu movie had moved the masses.  He also became popular by acting as a judge for the folk song program "Rela Re Rela" on Telugu TV channel, Maa.  He is one of the main Telangana separation activists.  He is one of the icons of Telangana culture.

Christmas lights: Christmas lights (also known as fairy lights) are lights used for decoration in preparation for Christmas and for display throughout the Christmastide.  The custom goes back to when we decorated Christmas trees with candles, which symbolize Christ being the light of the world; these were brought by Christians into their homes in early modern Germany.  Christmas trees displayed publicly and illuminated with electric lights became popular in the early 20th century.  By the mid-20th century, it became customary to display strings of electric lights as along streets and on buildings Christmas decorations detached from the Christmas tree itself.  In the United States, it became popular to outline private homes with such Christmas lights in tract housing beginning in the 1960s.  By the late 20th century, the custom had also been adopted in non-western countries / regions, notably in Japan and Hong Kong.  Throughout Christendom, Christmas lights continue to retain their symbolism of Jesus as the light of the world.

Vigiland: Vigiland is a Swedish house duo consisting of Claes Remmered Persson and Otto Pettersson from the small Swedish community Västervik, Sweden.  Their first single "Bouncer" became popular on Spotify when it was released in late 2013.  Upon releasing their Melbourne Bounce-influenced single "UFO", it made the top 10 of Spotify's most played songs.  With the release of their single "Shots & Squats", Vigiland achieved number-ones in Scandinavia over summer and autumn 2015.  "Shots & Squats" also became popular in Latin America due to Vine and after it was used as the theme for the MTV series "SuperShore".  In 2016, Vigiland released "Pong Dance", which reached number 2 in Sweden.

A Rush of Blood to the Head: A Rush of Blood to the Head is the second studio album by the British rock band Coldplay.  It was released on 26 August 2002 by Parlophone in the United Kingdom, and a day later by Capitol Records in the United States.  The album was produced by the band and producer Ken Nelson.  Recording started after the band became popular worldwide with the release of their debut album "Parachutes" (2000), and one of its singles in particular, "Yellow".  The album makes greater use of electric guitar and piano than its predecessor.

Yellow (Coldplay song): "Yellow" is a song by the British rock band Coldplay.  The band wrote the song and co-produced it with British record producer Ken Nelson for their debut album, "Parachutes" (2000).  The song's lyrics are a reference to the band's lead singer Chris Martin's unrequited love.

Soul music: Soul music (often referred to simply as soul) is a popular music genre that originated in the United States in the late 1950s and early 1960s.  It combines elements of African-American gospel music, rhythm and blues and jazz.  Soul music became popular for dancing and listening in the United States, where record labels such as Motown, Atlantic and Stax were influential during the Civil Rights Movement.  Soul also became popular around the world, directly influencing rock music and the music of Africa.

Toy book: Toy books were illustrated children's books that became popular in England's Victorian era.  The earliest toy books were typically paperbound, with six illustrated pages and sold for sixpence; larger and more elaborate editions became popular later in the century.  In the mid-19th century picture books began to be made for children, with illustrations dominating the text rather than supplementing the text.

Sarmu probo nisi: Sarmu probo nisi (, , meaning "You haven't tasted the sarma"), SPN, is a satirical political organization in Serbia formed in Mladenovac in 2016.  SPN started as a fictional political party created by a group of comedians from Mladenovac.  They became popular after they filmed a humorous parody promotional video for their fictional leader "Ljubiša Preletačević Beli".  After the video became popular on YouTube, they were persuaded by followers to participate in the election.  The group vowed to make a lot of false promises and false hope.  The focal point of their campaign was the promise to open a euthanasia department for pensioners in the local hospital in order to spare the country of their expenses.

Supporting paragraphs: A Rush of Blood to the Head Yellow (Coldplay song)
Answer: Ken Nelson