Question: What event held by the Ultimate Fighting Championship was the largest regulated professional MMA event?

full_context: Document 1: UFC 102: UFC 102: Couture vs. Nogueira was a mixed martial arts pay-per-view event held by the Ultimate Fighting Championship (UFC) on August 29, 2009 at the Rose Garden in Portland, Oregon. It featured former five-time UFC champion and UFC Hall of Famer Randy Couture, facing off against former PRIDE FC Heavyweight Champion and former Interim UFC Heavyweight Champion, Antônio Rodrigo Nogueira.
Document 2: UFC 114: UFC 114: Rampage vs. Evans was a mixed martial arts event held by the Ultimate Fighting Championship on May 29, 2010 at the MGM Grand Garden Arena in Las Vegas, Nevada. The UFC Fan Expo took place at the Mandalay Bay Convention Center.
Document 3: Mixed martial arts: Mixed martial arts (MMA) is a full-contact combat sport that allows both striking and grappling, both standing and on the ground, using techniques from other combat sports and martial arts. The first documented use of the term "mixed martial arts" was in a review of UFC 1 by television critic Howard Rosenberg in 1993. The term gained popularity when newfullcontact.com, then one of the largest websites covering the sport, hosted and republished the article. The question of who actually coined the term is subject to debate.
Document 4: UFC 112: UFC 112: Invincible was a mixed martial arts event held by the Ultimate Fighting Championship on April 10, 2010, in Abu Dhabi, United Arab Emirates. Due to the time zone difference in Abu Dhabi, UFC 112 was shown live on pay-per-view in the United States at 1 pm ET (10 am PT), with a replay at the regular time of 10 pm ET (7 pm PT).
Document 5: UFC 141: UFC 141: Lesnar vs. Overeem was a mixed martial arts pay-per-view event held by the Ultimate Fighting Championship on Friday December 30, 2011, at the MGM Grand Garden Arena in Las Vegas, Nevada.
Document 6: UFC 101: UFC 101: Declaration was a mixed martial arts pay-per-view event held by the Ultimate Fighting Championship (UFC) on August 8, 2009 in Philadelphia, Pennsylvania. It was the first ever UFC event held in Philadelphia. The event featured the second title defense of Lightweight Champion BJ Penn against Kenny Florian, and a non-title Light Heavyweight bout for Middleweight Champion Anderson Silva against former Light Heavyweight Champion Forrest Griffin.
Document 7: UFC 148: UFC 148: Silva vs. Sonnen II was a mixed martial arts event held by the Ultimate Fighting Championship on July 7, 2012 at the MGM Grand Garden Arena in Las Vegas, Nevada. It was the seventeenth UFC event of the year. The card consisted of eleven bouts, with six televised live on pay-per-view, four preliminary bouts on FX, and one on Facebook.
Document 8: UFC 140: UFC 140: Jones vs. Machida was a mixed martial arts event held by the Ultimate Fighting Championship on December 10, 2011 at the Air Canada Centre in Toronto, Ontario, Canada. It was the penultimate event for the UFC in 2011. The event featured eight bouts televised internationally, seven preliminary bouts aired on cable in the United States and Canada, and three preliminary bouts streamed live on Facebook. In the co-main event, Frank Mir, who was the first man to knock out Antônio Rodrigo Nogueira at UFC 92, became the first man to submit Nogueira. Mir accomplished the feat with a kimura that ultimately broke Nogueira's arm. In the main event, Lyoto Machida also suffered his first ever submission loss at the hands of Jon Jones. In doing so, Jones retained the UFC Light Heavyweight Championship title.
Document 9: UFC 129: UFC 129: St-Pierre vs. Shields was a mixed martial arts event held by the Ultimate Fighting Championship on Saturday, April 30, 2011 at Rogers Centre in Toronto, Ontario, Canada.
Document 10: Mixed martial arts in Ontario: Mixed martial arts (MMA) in Ontario had been considered illegal until August 14, 2010, when the Ontario government announced that they would be moving forward to allow professional mixed martial arts in the province. This was seen as a sudden change in direction as the government has been reluctant to allow MMA events to be held. This paved the way for the largest regulated professional MMA event, UFC 129, which was held on April 30, 2011 at the Rogers Centre in Toronto.
Document 11: 2001 in Maximum Fighting Championship: The year 2001 is the 1st year in the history of the Maximum Fighting Championship, a mixed martial arts promotion based in Canada. In 2001 Maximum Fighting Championship held 2 events beginning with, "MFC 1: Maximum Fighting".
Document 12: UFC 91: UFC 91: Couture vs. Lesnar was a mixed martial arts event held by the Ultimate Fighting Championship (UFC) on November 15, 2008 at the MGM Grand Garden Arena in Las Vegas, Nevada.
Document 13: UFC 30: UFC 30: Battle on the Boardwalk was a mixed martial arts event held by the Ultimate Fighting Championship at the Trump Taj Mahal in Atlantic City, New Jersey on February 23, 2001. UFC 30 was the first UFC event under the new ownership of Zuffa, LLC, and also the first UFC event since UFC 22 to see a home video release.
Document 14: UFC 134: UFC 134: Silva vs. Okami, also known as UFC Rio, was a mixed martial arts (MMA) pay-per-view event held by the Ultimate Fighting Championship on August 27, 2011 at the HSBC Arena in Rio de Janeiro, Brazil. The event was the second that the UFC has hosted in Brazil, since 1998's UFC 17.5: Ultimate Brazil. UFC 134 was awarded the 2011 event of the year by Sherdog.
Document 15: Maximum Fighting Championship: Maximum Fighting Championship is a Canadian mixed martial arts (MMA) promotion based in Edmonton, Alberta. MFC’s former home, in Canada, is the River Cree Resort and Casino in Enoch, Alberta, located just outside Edmonton, Alberta but has also held events at the Edmonton Expo Centre. MFC events are broadcast on The Fight Network, AXS TV (formerly HDnet) in North America and most recently TSN2. MFC is known to be the biggest MMA promotion in Canada and one of the top MMA shows in the World. MFC has notable Canadian fighters, such as Ryan Jimmo, Graham Spencer, Tom Watson and Douglas Lima, plus MMA veterans, such as Jason MacDonald, Thales Leites, Jay Silva, Trevor Prangley, and Paul Daley.
ground_truth: UFC 129