Question: The singer who contributed vocals to the track "You Know What It Is" was a member of what hip hop group?
Context: Nel Ust Wyclef Jean ( ; born on October 17, 1969), better known by his professional name Wyclef Jean, is a Haitian rapper, musician and actor.  At the age of nine, Jean emigrated as a child to the United States with his family and settled there.  He first achieved fame as a member of the New Jersey hip hop group the Fugees.  Jean has won three Grammy Awards for his musical work. "You Know What It Is" is a song by American hip hop recording artist T.I., released July 10, 2007, as the second single from his fifth studio album "T.I. vs. T.I.P." (2007).  The song was produced by Jerry "Wonda" Duplessis and Wyclef Jean, the latter of whom contributes vocals throughout the track.  It debuted at #73 on Billboard's R&B/Hip Hop Songs on June 28, 2007, later peaking at #11.  It later debuted on the "Billboard" Hot 100 at number 68 in July, later peaking at #34. Jason C. Medeiros better known as Mr. J. Medeiros, is an American Rapper, Record Producer, and Songwriter.  As well as releasing music under the name, Mr. J. Medeiros, he is responsible for forming the Hip Hop group The Procussions, is one half of the Hip Hop/Electronic duo AllttA, and the lead singer of Punk-Rap group KNIVES.  He is of Portuguese and Scottish descent.  Mr. J. has written music with such artists as, Monte Nueble, Noel Zancanella, Randy Jackson, Marty James, Shad (rapper), George "Spanky" McCurdy, Symbolyc One (S1), Illmind, Benny Cassette, Talib Kweli, 20Syl and French hip hop group Hocus Pocus (group) and more famous C2C. Herbert Brown, better known by his stage name McGruff (also known as Herb McGruff) is an American Hip hop recording artist from Harlem, New York City, New York.  Brown started rapping in his early teens.  He embarked on his music career in the hip hop group Bronx Most Wanted, alongside rappers Jay Q and Tee U.B. Brown later became a member of the hip hop collective Children of the Corn.  As a member of Children of the Corn, Brown worked alongside Big L, Cam'ron, Bloodshed and Mase, all of whom would go on to have successful careers in the music industry.  After the group disbanded without releasing any material, Brown made his first appearance on Big L's debut album, "Lifestylez ov da Poor & Dangerous" (1995), on the tracks "8 Iz Enuff" and "Dangerzone".  Eventually, Brown signed a deal with popular hip hop label, Uptown Records and began recording his debut album, "Destined to Be".  In early 1998, the album's lead single "Before We Start" became a minor hit, charting on several "Billboard" charts.  In the Summer of 1998, "Destined to Be" was released but failed to sell many copies, only peaking at 169 on the "Billboard" 200, and Brown was released from his contract.  Brown would make appearances with Heavy D on his album, "Waterbed Hev" and the "Woo" soundtrack.  In 2009, Brown appeared on Mase's mixtape "I Do the Impossible".  In 2010, he was featured heavily on The Diplomats mixtape, "The D.I.P. Agenda."  In 2014, DJ Kay Slay, enlisted Brown, along with Raekwon, Fat Joe, Ghostface Killah, Sheek Louch, N.O.R.E., Lil' Fame, Prodigy and Rell, for a song titled "90s Flow". Uptown 3000 was a Korean American hip hop duo on the record label The Machine Group CEO Alvin & Calvin Waters which consisted of Carlos Galvan aka "Cali-Mexci" and Steve Kim aka "Kwon".  The duo was a spinoff of Uptown, a Korean hip hop group which was active in the late 1990s whose sales reached 6 million.  The duo is considered defunct as the original Uptown made its comeback in Korea in 2006, which Kim and Galvan were a part of.  The group has been credited with being the first Korean hip hop group to closely resemble anything similar to American style hip hop. Quro (born Andrew Michael Bradley) is an Australian hip hop MC from Adelaide, South Australia who later relocated to Sydney.  He has been involved in the Australian hip hop scene since about 1992, when he formed part of the legendary Adelaide hip hop group Finger Lickin Good with MC Madcap.  Quro, as Andrew Bradley, has also worked on radio and as a journalist.  He also contributed a verse on the Def Wish Cast track "Saga (Iron Fist)" from their debut LP "Knights of the Underground Table". Robert Smith, better known by his stage name Rob Sonic, is a hip hop artist from The Bronx.  He is a former member of hip hop group Sonic Sum and a current member of hip hop group Hail Mary Mallon. "Old School Love" is a song by American hip hop recording artist Lupe Fiasco.  The song was released on October 14, 2013, in promotion of his fifth studio album "Tetsuo & Youth".  English singer Ed Sheeran contributed vocals to the song's hook.  The song peaked at number 93 on the US "Billboard" Hot 100 chart and number 18 on the New Zealand Singles Chart. Sons of the P is the second album by American rap group Digital Underground, released on October 15, 1991.  The album featured two hit singles, "No Nose Job" and "Kiss You Back", both of which were written by, and featured the lead vocals of Greg Jacobs (a.k.a. Shock G/Humpty Hump), and the latter of which featured multi-layered choruses and background vocals sung by Boni Boyer, who briefly worked with D.U. shortly after her stint with Prince's Sign of the Times/Love Sexy band.  It is sometimes mistakenly reported that Kiss You Back was co-written & co-performed by George Clinton, but his name appropriately appears in the writers credit due to a sample of "(Not Just) Knee Deep" by Funkadelic.  He did however actively participate in the writing and recording of the title track "Sons of the P", to which he also contributed vocals, and which marked one of the earliest studio guest appearances by Clinton on a Hip Hop release, preceded only by Kurtis Blow's "Magilla Gorilla" released in 1986.  Both the album and the single "Kiss You Back" were each certified Gold by the RIAA. Gregory Scott Owens, commonly known by his stage name Manchild (sometimes abbreviated as MC and previously known as Soulheir the Manchild) is a [[Christian hip hop|[[Christian rapper]] falls within the [[alternative hip hop]] genre.  He fronts the [[underground hip hop|underground]] and Christian hip hop group [[Mars ILL]], is part of the [[Deepspace5]] [[Supergroup (music)|supergroup]] [[Musical collective|collective]], and has collaborated with the likes of Christian rappers [[KJ-52]] and [[John Reuben]].  Manchild describes the origin of the name Soulheir in "Manchild Speaks" (a spoken word interlude found on "The Ringleader" by [[DJ Maj]]): "I used to know this cat named Soulheir / But I offed him, now I use his name often / Manchild is the cat that you wanna be quotin'."
Answer: Fugees