Question: In which city is the conference, where Texas Longhorns women's volleyball competes, headquartered?

Context paragraphs:
Texas Longhorns women's basketball: The Texas Longhorns women's basketball team represents The University of Texas at Austin in NCAA Division I intercollegiate women's basketball competition.  The Longhorns currently compete in the Big 12 Conference.

2009–10 Texas Longhorns women's basketball team: The 2009–10 Texas Longhorns women's basketball team represented University of Texas at Austin in the 2009–10 NCAA Division I basketball season.  The Longhorns were coached by Gail Goestenkors.  The Longhorns are a member of the Big 12 Conference.

2014 Texas Longhorns volleyball team: The 2014 Texas Longhorns volleyball team represented the University of Texas in the 2014 NCAA Division I women's volleyball season.  The Longhorns, led by 14th year head coach Jerritt Elliott, played their home games at Gregory Gymnasium.  The Longhorns were members of the Big 12 and were picked to win the conference title in the preseason poll.

2014–15 Texas Longhorns women's basketball team: The 2014–15 Texas Longhorns women's basketball team will represent the University of Texas at Austin in the 2014–15 college basketball season.  It will be head coach Karen Aston's third season at Texas.  The Longhorns were members of the Big 12 Conference and will play their home games at the Frank Erwin Center.  They finished the season 24–11, 9–9 in Big 12 play for a four way tie to finish in third place.  They advanced to the championship game of the Big 12 Women's Basketball Tournament where they lost to Baylor.  They received at-large bid of the NCAA Women's Basketball Tournament where they defeated Western Kentucky in the first round, California in the second round before losing to Connecticut in the sweet sixteen.

2013–14 Texas Longhorns women's basketball team: The 2013–14 Texas Longhorns women's basketball team will represent the University of Texas at Austin in the 2013–14 college basketball season.  It will be head coach Karen Aston's second season at Texas.  The Longhorns were members of the Big 12 Conference and will play their home games at the Frank Erwin Center.  They finished the season with a record of 22–12 overall, 11–7 in Big 12 play for a tie for a third-place finish.  They lost in the semifinals of the 2014 Big 12 Women's Basketball Tournament to West Virginia.  They were invited to the 2014 NCAA Women's Division I Basketball Tournament which they defeated Penn in the first round before getting defeated by Maryland in the second round.

Big 12 Conference: The Big 12 Conference is a ten-school collegiate athletic conference headquartered in Irving, Texas.  It is a member of the NCAA's Division I for all sports; its football teams compete in the Football Bowl Subdivision (FBS; formerly Division I-A), the higher of two levels of NCAA Division I football competition.  Its ten members, located in Iowa, Kansas, Oklahoma, Texas, and West Virginia, include eight public and two private Christian schools.  Additionally, the Big 12 has 12 affiliate members, eight for the sport of wrestling, one for women's gymnastics, and 3 for women's rowing.  The Big 12 Conference is a 501(c)(3) nonprofit organization incorporated in Delaware.

Texas Longhorns women's volleyball: The Texas Longhorns women's volleyball team represents The University of Texas at Austin in NCAA Division I intercollegiate women's volleyball competition.  The Longhorns currently compete in the Big 12 Conference.

Grand Canyon Antelopes: The Grand Canyon Antelopes are the 21 athletic teams representing Grand Canyon University in Phoenix, Arizona, more commonly referred to as the Lopes.  Most of the university's athletic teams compete at the NCAA Division I level in the Western Athletic Conference.  Men's volleyball competes in the Mountain Pacific Sports Federation (MPSF) effective beginning in the 2017-18 academic year.  The beach volleyball program competes as an independent.

2016–17 Texas Longhorns women's basketball team: The 2016–17 Texas Longhorns women's basketball team represents the University of Texas at Austin in the 2016–17 NCAA Division I women's basketball season.  It was head coach Karen Aston's fifth season at Texas.  The Longhorns were members of the Big 12 Conference and play their home games at the Frank Erwin Center.  They finished the season 25–9, 15–3 in Big 12 play to finish in second place.  They advanced to the semifinals of the Big 12 Women's Basketball Tournament where they lost to West Virginia.  They received at-large bid of the NCAA Women's Basketball Tournament where they defeated Central Arkansas and NC State in the first and second rounds before losing to Stanford in the sweet sixteen.

2015–16 Texas Longhorns women's basketball team: The 2015–16 Texas Longhorns women's basketball team represents the University of Texas at Austin in the 2015–16 college basketball season.  It was head coach Karen Aston's fourth season at Texas.  The Longhorns were members of the Big 12 Conference and play their home games at the Frank Erwin Center.  They finished the season 31–5, 15–3 in Big 12 play to finish in second place.  They advanced to the championship game of the Big 12 Women's Basketball Tournament where they lost to Baylor.  They received at-large bid of the NCAA Women's Basketball Tournament where they defeated Alabama State and Missouri in the first and second rounds, UCLA in the sweet sixteen before last year's sweet sixteen rematch to Connecticut in the elite eight.

Supporting paragraphs: Texas Longhorns women's volleyball Big 12 Conference
Answer: Irving