Concept:The purchases day book is used to record all goods bought on credit, and the source document for each such entry is the supplier’s invoice.
Explanation:A purchases day book records only credit purchases of goods.
For every credit purchase, the buyer receives an invoice from the supplier.
The invoice shows the date, supplier name, items bought, quantity, price, and total amount.
Therefore, the invoice is the document from which the entry is transferred into the purchases day book.
The other options are not used for this purpose.
A waybill is issued for delivery of goods.
A credit note is issued by a seller to reduce the amount owed, often for returns.
A receipt is given when cash or cheque payment is made.
Thus, these documents do not support the recording of credit purchases in the purchases day book.
Answer:D. invoice