An invoice received included the following information: merchandise price, $6,100; terms 1/10, n/eom; FOB shipping point with prepaid freight of $506. Assuming that a credit for merchandise returned of $1,200 is granted prior to payment and that the invoice is paid within the discount period, what amount of cash should be paid by the buyer?

a. $5,357

b. $6,100

c. $1,200

d. $6,540