No, the first Avatar in 2009 was put out by 21st Century Fox. The second and third Avatars will also be by produced by 21st Century FOX however thanks to the acquisition of 21st Century FOX by Disney in December 2017 [finalized by Summer 2019], the third and fourth Avatars [assuming they are made] will in fact be Disney productions.

The 21st century began on January 1, 2001

No she isn't wrestling anymore but still loves it.

It depends on which century are you talking about. 20th century? Porfirio Diaz was the Mexican president at the time. 21st century? Vicente Fox was such leader.

21st Century - 2007 was released on:

USA: 1 January 2007

UK: 1 January 2008