Concept:Credit and debit notes are used to correct errors in the amount charged for goods sold, especially when a buyer is overcharged or undercharged.
Explanation:When a seller overcharges the buyer on an invoice, the seller issues a credit note to reduce the amount payable.
When a seller undercharges the buyer, the buyer may issue a debit note to record the extra amount owed, or the seller may issue a debit note to demand the shortfall.
These notes are not needed simply when goods are received from a supplier or when goods are sold normally.
They are also not connected with extracting a trial balance, since that is an internal accounting check.
Credit and debit notes are therefore applied only when the buyer is charged the wrong amount and the invoice must be adjusted.
This condition is exactly described as the buyer being under or over charged.
Answer:C. When a buyer is under or over charged