Question: What conference did former Oklahoma Sooners star Willie Warren play in?
Context: The 1989–90 Oklahoma Sooners men's basketball team represented the University of Oklahoma in competitive college basketball during the 1989–90 NCAA Division I season.  The Oklahoma Sooners men's basketball team played its home games in the Lloyd Noble Center and was a member of the National Collegiate Athletic Association's (NCAA) former Big Eight Conference at that time.  The team posted a 27–5 overall record and an 11–3 conference record to finish tied for second in the Conference for head coach Billy Tubbs.  This was the third Big Eight Conference Tournament Championship for Tubbs and his third NCAA Men's Division I Basketball Tournament #1 seed in a row.  The team earned the conference tournament championship competing in a conference in which three teams held the #1 national ranking in consecutive weeks in late February and early March. The 1983–84 Oklahoma Sooners men's basketball team represented the University of Oklahoma in competitive college basketball during the 1983–84 NCAA Division I season.  The Oklahoma Sooners men's basketball team played its home games in the Lloyd Noble Center and was a member of the National Collegiate Athletic Association's (NCAA) former Big Eight Conference at that time.  The team posted a 29–5 overall record and a 13–1 conference record to finish first in the Conference for head coach Billy Tubbs.  This was the first Big Eight Conference Regular Season Championship for Tubbs. Willie D. Warren (born October 22, 1989) is an American professional basketball player for Petrochimi Bandar Imam of the Iranian Basketball Super League.  He played college basketball for Oklahoma. The 1984–85 Oklahoma Sooners men's basketball team represented the University of Oklahoma in competitive college basketball during the 1984–85 NCAA Division I season.  The Oklahoma Sooners men's basketball team played its home games in the Lloyd Noble Center and was a member of the National Collegiate Athletic Association's (NCAA) former Big Eight Conference at that time.  The team posted a 31–6 overall record and a 13–1 conference record to finish first in the Conference for head coach Billy Tubbs.  This was the first Big Eight Conference Tournament Championship and second Conference Regular Season Championship for Tubbs.  This was Tubbs' first NCAA Men's Division I Basketball Tournament #1 seed. The 1984 Oklahoma Sooners football team represented the University of Oklahoma in the college football 1984 NCAA Division I-A season.  Oklahoma Sooners football participated in the former Big Eight Conference at that time and played its home games in Gaylord Family Oklahoma Memorial Stadium where it has played its home games since 1923.  The team posted a 9–2–1 overall record and a 6–1 conference record to earn a share of the Conference title under head coach Barry Switzer who took the helm in 1973.  This was Switzer's ninth conference title in twelve seasons. The 1979 Oklahoma Sooners football team represented the University of Oklahoma in the college football 1979 NCAA Division I-A season.  Oklahoma Sooners football participated in the former Big Eight Conference at that time and played its home games in Gaylord Family Oklahoma Memorial Stadium where it has played its home games since 1923.  The team posted an 11–1 overall record and a 7–0 conference record to earn the Conference title outright under head coach Barry Switzer who took the helm in 1973.  This was Switzer's seventh conference title and fourth undefeated conference record in seven seasons. The 1978–79 Oklahoma Sooners men's basketball team represented the University of Oklahoma in competitive college basketball during the 1978–79 NCAA Division I season.  The Oklahoma Sooners men's basketball team played its home games in the Lloyd Noble Center and was a member of the National Collegiate Athletic Association's (NCAA) former Big Eight Conference at that time.  The team posted a 21–10 overall record and a 10–4 conference record to finish first in the Conference for head coach Dave Bliss.  This was the only Big Eight Conference Regular Season Championship for Bliss. The 1987–88 Oklahoma Sooners men's basketball team represented the University of Oklahoma in competitive college basketball during the 1987–88 NCAA Division I men's basketball season.  The Oklahoma Sooners men's basketball team played its home games in the Lloyd Noble Center and was a member of the National Collegiate Athletic Association's (NCAA) former Big Eight Conference at that time.  The team posted a 35–4 overall record and a 12–2 conference record to earn the Conference title under head coach Billy Tubbs.  This was the third Big Eight Conference Regular Season Championship for Tubbs and his second Big Eight Conference Tournament Championship. The 1978 Oklahoma Sooners football team represented the University of Oklahoma in the college football 1978 NCAA Division I-A season.  Oklahoma Sooners football participated in the former Big Eight Conference at that time and played its home games in Oklahoma Memorial Stadium where it has played its home games since 1923.  The team posted an 11–1 overall record and a 6–1 conference record to earn a share of the conference title under head coach Barry Switzer.  This was Switzer's sixth conference title in six seasons since taking the helm in 1973. The Oklahoma Sooners men's basketball team represents the University of Oklahoma in men's NCAA Division I basketball.  The Sooners play in the Big 12 Conference.
Answer: Big 12 Conference.