The correct option is C Findlay Shirras
"National debt is a debt which a State owes to its subjects or to the nationals of other countries". It was defined by Findlay Shirras. In simple words, Public Debt refers to loan raised by the government within the country or outside the country. the government may borrow from individuals, business enterprises and banks, etc. when its expenditure exceeds its revenue. But it is not a source of revenue like tax.