Correct Answer : Option (A) - It was considered a source of income for the State, a sort of tax paid by the people.
Vishti was form of forced labour extracted by either state, provincial governor or local chief. It is also mentioned on Gupta era copper inscriptions that enlist variety of taxes.
Junagarh inscription mentions vishti as one form of tax, which indicates that it was extracted from Gujarat and Malwa region. Since it was a forced labour in lieu of tax, it was not a wage labour. Wage labour existed in ancient India but it was not called vishti. Vishti could be extracted from anyone, not in particular from eldest son only.