Open question: Explaining assistance needs!!!!!!!!!!!!!?

Invoices covered the following information: Commodity price, $5.000; Delivery expenses, $300; Expressions 1/10, n/eom, FOB Verschiffenpunkt. Assuming that a credit note for the goods, which are returned of $600 before payment is granted that the delivery expenses are paid by the customer and that the calculation is paying within the discounting period, is which the quantity of the cash received from the salesman? a. $4,656 B. $4,400 C. $4,356 D. $4.950