Use the following account numbers and corresponding account titles to answer the following question.
Account No. Account Title
(1) Cash
(2) Merchandise inventory
(3) Cost of goods sold
(4) Transportation-out
(5) Dividends
(6) Common stock
(7) Selling expense
(8) Loss on the sale of land
(9) Sales
Which accounts would affect gross margin?
a. Account numbers 3, 4, 7 and 9
b. Account numbers 3, 7, 8 and 9
c. Account numbers 2 and 9
d. Account numbers 3 and 9