Concept:A means of payment is a commonly accepted instrument that can be used to settle debts or buy goods and services.
Explanation:Postal orders are prepaid payment instruments issued by the Post Office.
They are used to pay a specified sum of money to a named person.
I.O.U and promissory notes are only written promises to pay later, not direct means of payment.
C.I.F refers to cost, insurance, and freight, which is a trade term, not a payment method.
Answer:The correct answer is B. Postal order.