Which one of the following mentioned division of the Mauryan Society into seven classes?

Indica is the book written by Megasthenes, the Greek ambassador to India around 300 Be. The division of Maurya society into seven classes was particularly mentioned in the 'Indica' of Megasthenes. The Indians generally were divided into seven categories, the wise men (Brahmins), farmers, herdsmen, artisans, soldiers, over lookers and government officials including army and navy officers.