Concept:Legal tender refers to money that must be accepted if offered in payment of a debt.Explanation:Bank notes and coins are the standard forms of legal tender in an economy.They are issued by the central bank and are backed by law.A cheque and a traveller's cheque are not legal tender because they may be refused by a creditor.A goldsmith receipt is only a document of deposit, not a legal medium of payment.Therefore, the only item that qualifies as legal tender is the bank note.Answer:C. Bank note