Simplify the following text for a Grade 12 native English-speaking person.
Original: It is an active member of USA Basketball ( USAB ) , which is recognized by the International Basketball Federation as the National Governing Body ( NGB ) for basketball in the United States . The NBA is one of the four major North American professional sports leagues , which include Major League Baseball ( MLB ) , the National Football League ( NFL ) , and the National Hockey League ( NHL ) .
Simplified: The National Basketball Association ( NBA ) is the world 's top men 's professional basketball league and one of the major professional sports leagues of North America only .