Question: Which Big East champion began his NBA career with the Celtics in 2007?

Context paragraphs:
2014 Big East Men's Basketball Tournament: The 2014 Big East Men's Basketball Tournament, officially known as the 2014 Big East Championship, was the 35th overall edition of the Big East Men's Basketball Tournament, but the first of the current Big East Conference.  It determined the recipient of the conference's automatic bid to the 2014 NCAA Tournament, as well as one of the two (or more) officially recognized conference champions for the 2013–14 Big East Conference men's basketball season (like most NCAA Division I conferences, the Big East recognizes both the regular-season and tournament winners as conference champions).  It was held at Madison Square Garden in New York City.

2013 Big East Men's Basketball Tournament: The 2013 Big East Men's Basketball Tournament, officially known as the 2013 Big East Championship, was the 34th annual Big East Men's Basketball Tournament, deciding the champion of the 2012–13 Big East Conference men's basketball season.  For the 31st consecutive season, the tournament was held at Madison Square Garden in New York City, from March 12–16, 2013.  The tournament only featured 14 teams due to Connecticut being given a one-year postseason ban due to APR penalties.  This would have been the last year with as many as 16 teams participating in the Big East tournament, but Connecticut was ineligible and West Virginia moved to the Big 12 before the beginning of the season.  The conference tournament champion received an automatic bid to the 2013 NCAA Tournament.

Chauncey Billups: Chauncey Ray Billups (born September 25, 1976) is an American retired professional basketball player who played 17 seasons in the National Basketball Association (NBA).  A star at the University of Colorado, he was selected third overall in the 1997 NBA draft by the Boston Celtics.  A five-time NBA All-Star and a three-time All-NBA selection, Billups played for the Celtics, Toronto Raptors, Denver Nuggets, Minnesota Timberwolves, Detroit Pistons, New York Knicks, and Los Angeles Clippers during his NBA career.  He won the NBA Finals MVP in 2004 after helping the Pistons beat the Los Angeles Lakers in the Finals, and was given the nickname "Mr. Big Shot" for making late-game shots with Detroit.  The Pistons retired his number #1 jersey in 2016.

Jeff Green (basketball): Jeffrey Lynn Green (born August 28, 1986) is an American professional basketball player for the Cleveland Cavaliers of the National Basketball Association (NBA).  He played three seasons of college basketball for Georgetown, before entering the 2007 NBA draft, where he was selected fifth overall by the Boston Celtics.  He was subsequently traded to the Seattle SuperSonics (now known as the Oklahoma City Thunder).  He spent four seasons with the franchise before being traded back to the Celtics during the 2010–11 season, where he played until 2015 before being traded to the Memphis Grizzlies.  In 2016, he was traded to the Los Angeles Clippers.  He spent half a season with the Clippers before joining the Magic following the 2015–16 season.

2013 Big East Conference men's soccer season: The 2013 Big East Conference men's soccer season is the inaugural season for the newly formed offshoot of the original Big East Conference.  The "new" Big East consists of the seven members of the original Big East that did not sponsor Division I FBS football (the so-called "Catholic 7"), plus invited founding members Butler, Creighton, and Xavier.  The FBS schools sold the "Big East" name to the "Catholic 7" and are operating as the American Athletic Conference under the original Big East charter.  Including the history of the original Big East, this will be the 18th season of men's soccer under the "Big East" name.

2007 Big East Men's Basketball Tournament: The 2007 Big East Men's Basketball Championship was played from March 7 to March 10, 2007.  The tournament took place at Madison Square Garden in New York City and was sponsored by Aéropostale.  The Georgetown Hoyas won the tournament for the first time since 1989 and the seventh time overall, and were awarded an automatic bid to the 2007 NCAA Men's Basketball Tournament.  Jeff Green of Georgetown was given the Dave Gavitt Trophy, awarded to the tournament's most outstanding player.

2003 Big East Men's Basketball Tournament: The 2003 Big East Men's Basketball Tournament, a part of the 2002–03 NCAA Division I men's basketball season, took place from March 12 – March 15, 2003 at Madison Square Garden in New York City.  Its winner will receive the Big East Conference's automatic bid to the 2003 NCAA Tournament.  It was a single-elimination tournament with four rounds and the four highest seeds (two from each Big East division) receive byes in the first round.  The 6 Big East teams with the best conference records from both the East and West Divisions of the Big East Conference were invited to participate.  Boston College, who had an identical 10–6 record as Connecticut, received the #1 seed from the East Division due to a tie breaker.  Likewise, Syracuse, who had an identical 13–3 conference record to Pitt, received the #1 seed from West Division due to tiebreakers.  Virginia Tech from the East Division and Rutgers from the West Division failed to make the tournament. <br>

Providence Friars: The Providence Friars is the name of the athletic teams of Providence College.  They compete in the Big East Conference (NCAA Division I) for every sport except for ice hockey, where they compete in Hockey East.  The Big East Conference was founded in 1979 by former athletic director and men's basketball coach Dave Gavitt.  On December 15, 2012, Providence and the other seven Catholic, non-FBS schools announced that they were departing the Big East for a new conference; on March 7, 2013, it was officially confirmed that Providence's new conference would operate under the Big East name.  The women's volleyball team, which had been an associate member of the America East Conference before the Big East split, remained in that conference for one more season before joining the Big East for the 2014 season.

Bobby Curtis (runner): Robert "Bobby" M. Curtis (born November 28, 1984) is an American long-distance runner formerly of Villanova University.  He is a multiple-time Big East Champion and NCAA All-American in both cross country and track and field.  Curtis' greatest collegiate achievement came in 2008, when he won the NCAA Division I National Championship in the 5000m.  He is currently a professional runner sponsored by Brooks Sports training with the Hansons-Brooks Distance Project.

2008 Fiesta Bowl: The 2008 Tostitos Fiesta Bowl was a college football bowl game.  It was part of the 2007–2008 Bowl Championship Series (BCS) of the 2007 NCAA Division I FBS football season.  Played annually since 1971, first at Sun Devil Stadium on the campus of Arizona State University in Tempe, Arizona through 2006, the game was played at 8 p.m. EST on January 2, 2008, at the University of Phoenix Stadium in Glendale, Arizona.  The game featured the fourth ranked (BCS), Big 12 champion Oklahoma Sooners hosting the ninth ranked (BCS), Big East champion West Virginia Mountaineers.  West Virginia defeated Oklahoma by a score of 48–28.  The contest was televised on Fox.

Supporting paragraphs: 2007 Big East Men's Basketball Tournament Jeff Green (basketball)
Answer: Jeff Green