Using the perpetual inventory system, journalize the entries for the following selected transactions:
a. Sold merchandise on account for $12,000, terms n/30. The cost of the goods sold was $6,500.
b. Sold merchandise to customers who used MasterCard and VISA, $9,500. The cost of the goods sold was $5,300.
c. Sold merchandise to customers who used American Express, $2,900. The cost of the goods sold was $1,700.
d. Paid an invoice from First National Bank for $385, representing a service fee for processing MasterCard and VISA sales.
e. Paid an invoice from American Express for $75 fee.