Question: Which arena, once known as the "North Greenwich Arena", regularly hosts the Country to Country music festival?
Context: Pettigrew Green Arena is a multi-purpose indoor sports and entertainment centre in Taradale near Napier, New Zealand.  The centre opened in April 2003, and regularly hosts volleyball, basketball and netball matches for Hawke's Bay representative teams.  The main court has a capacity of 2,500.  The centre hosted an ANZ Championship match for the Central Pulse against the Adelaide Thunderbirds in Round 14 of the 2008 season.  The Arena is also home to the Hawke's Bay Hawks. Rupp Arena is an arena located in downtown Lexington, Kentucky, U.S. Since its opening in 1976, it has been the centerpiece of Lexington Center, a convention and shopping facility owned by an arm of the Lexington-Fayette Urban County Government, which is located next to the Lexington Hyatt and Hilton hotels.  Rupp Arena also serves as home court to the University of Kentucky men's basketball program, and is named after legendary former Kentucky coach and University of Kansas alumnus Adolph Rupp.  With an official capacity of 23,500, it is currently the largest arena in the United States designed specifically for basketball, and is also the largest indoor arena by capacity in the USA.  In Rupp Arena, the Kentucky Wildcats men's basketball team is second in the nation in college basketball home attendance.  The only other basketball-specific arena in US history larger than the arena is the now-demolished Charlotte Coliseum.  Rupp Arena also regularly hosts concerts, conventions and shows. Basketball at the 2012 Summer Olympics was held from 28 July to 12 August 2012.  The preliminary matches and the women's quarterfinal matches were played in the new Basketball Arena in Olympic Park which seated up to 12,000 spectators.  The men's knockout games and the women's games from semifinals onward were played in the North Greenwich Arena. The Boots and Hearts Music Festival is a multi-day country music and camping festival produced by Republic Live Inc. and owned by Stan and Eva Dunford.  It is held annually at the custom-designed festival grounds, Burl’s Creek Event Grounds in Oro-Medonte, Ontario, Canada.  Since its inception in 2012, Boots and Hearts has quickly grown to become Canada's largest country music festival and considered the second largest music festival in North America behind only the CMA Music Festival.  The festival offers multiple stages, meet and greets, VIP offerings, an on-site farmers market, and more to 45,000+ festival-goers over the course of 4 days.  Boots and Hearts was awarded the CCMA (Canadian Country Music Association) “Festival of the Year” Award in 2014, 2015, and 2016, as well as the Canadian Music Week “Festival of the Year” in 2015, with repeat nominations in 2016 and 2017.  Boots and Hearts has seen the acts of world-renowned artists such as Carrie Underwood, Luke Bryan, Blake Shelton, Toby Keith, Jason Aldean, Miranda Lambert, Tim McGraw, Rascal Flatts, Brad Paisley, Eric Church, Florida Georgia Line and many other country music stars.  The 2017 edition of Boots and Hearts Music will be taking place from August 10 – 13, 2017.  { Three gymnastics disciplines were contested at the 2012 Olympic Games in London: artistic gymnastics, rhythmic gymnastics and trampolining.  The trampoline events were held at the North Greenwich Arena (normally called The O2 Arena) from 3 to 4 August; the artistic events were also held at the North Greenwich Arena, from 28 July to 7 August.  The rhythmic gymnastics events took place at Wembley Arena from 9 to 12 August. Bught Park (Gaelic: Pàirc nam Bochd ) is the largest park in the city of Inverness, Scotland, and is situated on the western bank of the River Ness.  It is home to the Inverness Highland Games and a small scale outdoor music festival.  It is located next to the city's sports centre, swimming pool and BMX track.  The Bught Park is also the name for the sports stadium situated within the confines of the park which regularly hosts both the Camanachd Cup Final and the Composite Rules Shinty/Hurling Internationals and is considered one of the finest parks in shinty.  It is also home to Inverness Shinty Club who have played there since the 1920s. The O2 Arena (temporarily the sponsor-neutral "North Greenwich Arena", during the 2012 Summer Olympics and 2012 Summer Paralympics), is a multi-purpose indoor arena located in the centre of The O2 entertainment complex on the Greenwich Peninsula in south-east London.  The arena was built under the former Millennium Dome, a large dome-shaped building built to house an exhibition celebrating the turn of the third millennium; as the dome-shaped structure still stands over the arena, "The Dome" remains a name in common usage for the venue.  The arena, as well as the total O2 complex, is named after its primary sponsor, the telecommunications company O. North Greenwich is a 19th-century name for the southern tip of the Isle of Dogs, located in the London Borough of Tower Hamlets.  It was named for the now defunct North Greenwich railway station (1872), that served a former passenger ferry to Greenwich and stood near the later Island Gardens (1897) and Greenwich foot tunnel (1902).  It faces Greenwich over the River Thames and the area is now more usually known as South Millwall.  Millwall Football Club played in this area from 1901–1910, naming their ground North Greenwich. C2C: Country to Country is a country music festival which takes place at The O2 Arena in London every year.  It was first held on 16–17 March 2013.  The festival was the first multi-day country music event in the United Kingdom, since the demise of the popular International Festival of Country Music, which was held at Wembley Arena and hosted by Mervyn Conn.  The event was jointly developed by the O2 Arena and SJM Concerts, collaborating with the Country Music Association. North Greenwich is a London Underground station served by the Jubilee line.  Despite its name, it is not in the area historically known as North Greenwich, on the Isle of Dogs, north of the River Thames; an entirely different North Greenwich station used to be there, between 1872 and 1926.  It is actually closer to Charlton than to Greenwich, however, it is at the northernmost tip of the Royal Borough of Greenwich, which perhaps provides the best explanation of the name.
Answer: The O2 Arena