Tiger JK (Birth name: Seo Jung-kwon, Hangul: 서정권, Hanja: 徐廷權; born July 29, 1974) is a South Korean rapper, record producer and entrepreneur best known as a founding member of Korean hip hop group Drunken Tiger.
 He has also founded two record labels, Jungle Entertainment and Feel Ghood Music.
 He is currently a member of hip hop trio MFBTY.
Willis Polk II, better known by his stage name Deacon the Villain, is an American hip hop recording artist and record producer from Versailles, Kentucky.
 He is a founding member of the hip hop group CunninLynguists.
 Deacon's has produced for the likes of KRS-One, King Tee, and J-Ro from Tha Liks, among others.
 Deacon the Villain has been featured in notable journalism sources such as XXL, Pop Matters, HipHopDX, and Exclaim!
, among others.
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".
Adam Nathaniel Yauch (pronounced ; August 5, 1964 – May 4, 2012) was an American rapper, musician, songwriter, director and film distributor.
 He was best known as a founding member of the hip hop group Beastie Boys.
 He was frequently known by his stage name, MCA, and sometimes worked under the pseudonym Nathanial Hörnblowér.
Darryl "D.M.C." Matthews McDaniels (born May 31, 1964) is an American musician.
 He is a founding member of the hip hop group Run–D.M.C., and is considered one of the pioneers of hip hop culture.
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.
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.
Serbian hip hop refers to all genres of hip hop music in the Serbian language.
 The term is also sometimes used to refer to any hip hop music made by Serbs, including instrumental hip hop, as well as rap songs by members of the Serbian diaspora, often in languages other than Serbian.
 Beogradski Sindikat is considered to be the greatest Serbian hip hop group, along with others like VIP, Sunshine, CYA.
 The most popular solo artists are Skabo, Ikac, Reksona, Juice, Gru, Struka, Ajs Nigrutin, Marchelo, etc.
Rahem Brown (born March 20, 1970), better known by his stage name Tame One, is an American hip hop recording artist from New Jersey.
 He is founding member of duos such as Artifacts and Leak Bros, as well as the hip hop supergroup The Weathermen.
 Tame One, along with Jay Burnz Jay, are Founder and Co-founder of the super hip hop group The Boom Skwad since 1992, of which Tame One is President.
 He appointed Jay Burnz Jay as Vice President of The Boom Skwad.
Elwood is the musical project/collaboration of singer-songwriter Prince Elwood Strickland III (born in North Carolina) and co-producer and songwriter Brian Boland.
 Strickland worked as a recording engineer at Soho's Greene Street Recording facility where he and Boland met, working with artists such as Tricky, Mos Def, De La Soul, and Adam Yauch.
 Elwood worked with producer Steve Lillywhite on their debut album "The Parlance of Our Time", which was co-released on Palm Pictures and Lillywhite's label, Gobstopper.

Question: Elwood worked with MCA, who was the founding member of what hip hop group?
Answer: Beastie Boys