Sentence:  Denying this claim, the Buddha tells Assalayana how in Yona and <WSD>Kamboja</WSD> and other outlying regions there are two "vannas", the master and the slave, and that it is possible for a master to become a slave or for a slave to become a master. 
Meaning of the word marked with <WSD> tags:  An ancient Indo-Iranian region, located originally in Central Asia.