Concept:A supplier uses a credit note to correct an invoice that overstated the amount a customer owes.
Explanation:Overcasting an invoice means the total amount was calculated above the correct value.
As a result, the customer is asked to pay more than the actual cost.
The supplier is responsible for correcting this error promptly.
The appropriate document for this correction is a credit note.
The credit note shows the reduced amount and is applied against the customer's outstanding balance.
It informs the customer that the supplier has credited the excess amount to the customer's account.
A debit note is sent when the invoice was understated, so it is not used in this case.
Thus, the supplier will send a credit note to the customer.
Answer:Credit note (Option C).