Concept:A source document is an original business record that supports a transaction.
We need to identify which option is not a source document.
Explanation:Sales invoices, debit notes, and credit notes are all official source documents.
They are used as evidence for sales, returns, and adjustments.
The journal paper is not a separate source document.
A journal paper is simply a book of original entry used for recording transactions.
It is not the original evidence for a transaction.
It relies on actual source documents like invoices or notes.
Therefore, the correct answer is journal paper.
Answer:A. journal paper