What does "C.O.D." represent in postal terminology?

In postal terminology, "C.O.D." stands for Cash on Delivery. This service allows the sender to require the recipient to pay for a package at the time of delivery. It's particularly useful in situations where the seller wants to ensure they receive payment before releasing the merchandise to the buyer, mitigating the risk of non-payment.

Using C.O.D. is common in transactions involving mail-order purchases, where buyers might not be familiar with the seller or want the guarantee of inspecting goods before payment. This provides a level of assurance for both parties: the sender can ensure payment, while the recipient can confirm the item’s condition before handing over cash.

The other options do not accurately reflect postal terminology related to payment upon delivery, which is why they are not the correct answer. Certificate of Deposit typically refers to a financial product used in banking; Cash on Demand implies an immediate payment transaction, but does not align with the specifics of postal delivery services; and Credit on Delivery suggests a credit transaction which also doesn't fit the context of mailing services.