Question: Who produced Kelis most well-known song?
Context: "Milkshake" is a song by American recording artist Kelis and the lead single from her third studio album, "Tasty".  It was originally offered to Britney Spears for her fourth studio album "In the Zone", but was rejected for unknown reasons.  The song was released in the United States on August 26, 2003, by Star Trak and Arista Records, and internationally on November 24.  It was written and produced by The Neptunes, a duo that had made the majority of Kelis' songs in the past.  According to Kelis, "milkshake" in the song is used as a metaphor for "something that makes women special."  The song is noted for its euphemistic chorus and low beat R&B sound. "Millionaire" is a song by American singer-songwriter Kelis, featuring American rapper André 3000.  It was released on October 18, 2004 as the third single from Kelis' third studio album, "Tasty" (2003).  The song was written by Kelis and André 3000, the latter of whom also produced it.  Like Kelis' previous single "Trick Me", "Millionaire" was not released in the United States.  The track contains a sample of the 1985 song "La Di Da Di" by Doug E. Fresh and Slick Rick. "Shake Ya Ass", also known by its clean title, "Shake It Fast", is the 1st single released from American rapper Mystikal's album, "Let's Get Ready".  It also featured uncredited vocals from Pharrell.  It was released July 18, 2000 and produced by The Neptunes.  It was a huge success for Mystikal, peaking at #13 on the Billboard Hot 100, #3 on the Hot R&B/Hip-Hop Songs and #7 on the Hot Rap Singles.  Both the song and music video (directed by Little X) received heavy airplay and it has arguably become Mystikal's most well-known song.  "Shake Ya Ass" was followed by another top 20 hit, "Danger (Been So Long)". Kelis Rogers ( ; born August 21, 1979), better known mononymously as Kelis, is an American singer, songwriter and chef.  Kelis achieved moderate international success with her 1999 debut album, "Kaleidoscope", but left her label Virgin Records after its follow-up, "Wanderland" (2001), received little sales attention and no U.S. release.  Her third album, 2003's "Tasty", earned the singer commercial prominence and produced the hit single "Milkshake", her most well-known song. " Kelis Was Here" (2006), her fourth album, was the subject of further label disputes and she took a hiatus from music after its release, during which she trained at Le Cordon Bleu culinary school.  She released the album "Flesh Tone" in 2010 and her sixth, "Food", under Ninja Tune Records in 2014. The following is a list of episodes for the Japanese anime series "Ergo Proxy".  "Ergo Proxy" was produced by Manglobe Inc. and directed by Shukou Murase.  It began broadcasting in Japan on February 25, 2006, on WOWOW.  The English version the anime is licensed by Geneon Entertainment.  "Ergo Proxy" was a DVD-only series, until syndication of the series on the Fuse channel began on June 9, 2007 at 12:30 a.m.  The series' opening theme song is "Kiri" by rock group Monoral, and is first shown in episode 3.  The ending theme song is "Paranoid Android", a well-known song by English alternative rock band Radiohead.  Another ending is on the Hulu version. "Good Stuff" is a song by American R&B singer-songwriter Kelis from her debut album, "Kaleidoscope" (1999).  Written and produced by The Neptunes, the song was released as the album's second single, and features a guest appearance from American rapper Pusha T, formerly known as Terrar, one half of the hip hop duo Clipse.  The single failed to chart on the U.S. "Billboard" Hot 100 and only managed limited success in select European markets, but nevertheless became a second top twenty hit for Kelis on the UK Singles Chart, peaking at number nineteen. "Scream" is a song performed by American recording artist Kelis, taken from her fifth studio album, "Flesh Tone", written by Kelis and Jean Baptiste, and co-written and produced by David Guetta and El Tocadisco.  It was released in October 2010, as the album's third single by will.i.am music, to coincide with the European leg of the Kelis' All Hearts tour.  It was mainly met with positive reception from music critics, who praised the song's genre-shifting production and the empowering message in Kelis' lyrics. "I Don't Think So" is a song by American singer Kelis from her fourth studio album, "Kelis Was Here" (2006).  It was written by Kelis, Max Martin, and Dr. Luke, and produced by the latter two.  The song became popular with Australian audiences after being used in advertisements for the 2008 season of "Big Brother Australia".  Following the successful promotion of the show in Australia, the second season of "American Gladiators" used the same song and concept in their advertisements in the United States. "Je t'aimais, je t'aime, je t'aimerai" (""I have loved you, I love you and I will love you"") is a well-known song by French singer and songwriter Francis Cabrel.  It is considered his most definitive song, alongside his other classic "Je l'aime à mourir".  The song was written by Cabrel and is taken from his 1994 album "Samedi soir sur la terre", which was released in 1994 and is Cabrel's biggest selling album.  The song was produced by Gérard Bikialo. "Young, Fresh n' New" is a song by American recording artist Kelis from her second studio album, "Wanderland".  Written by Kelis and The Neptunes members Pharrell Williams and Chad Hugo—who also produced the track—, it was released as the album's only single in 2001, becoming a minor hit in the United Kingdom, where it peaked at number thirty-two on the UK Singles Chart.  In the United States, however, it became her third consecutive single to miss the "Billboard" Hot 100, while "Wanderland" remains unreleased there.  Nevertheless, the song's Timo Maas remix did manage to chart on "Billboard"' s Hot Dance Club Play at number fifteen in late January 2002.
Answer: The Neptunes