Final answer:
In a sale on account, the financial risk of non-payment is undertaken by the seller, since they provide the goods or services before payment is made.
Step-by-step explanation:
In a sale on account, the party undertaking a financial risk of non-payment is C) The seller. This type of transaction involves the seller providing goods or services to the buyer with the understanding that payment will be made at a later date. During the interval between the sale and the receipt of payment, the seller bears the risk that the buyer may default on the obligation. This risk is mitigated to some extent by the seller's ability to pursue legal action or employ collection services, though there is no guarantee of full recovery. Therefore, the financial risk associated with non-payment principally rests with the seller.