in the transaction bought supplies on account from wake supply co., the source document is a/an:\na…

Brief Explanations:

When supplies are bought on account, the source document is an invoice. An invoice is provided by the seller (Wake Supply Co. in this case) to the buyer, detailing the goods or services provided, the amount due, and payment terms. A memorandum is more for internal - company notes. A check stub is related to payments made by check. A receipt is given after payment is made, while here the purchase is on account (credit), so an invoice is issued first.

Answer:

C. invoice