Trent Department Store uses a perpetual inventory system but adjusts its inventory records at year-end to reflect the results of a complete physical inventory. In the physical inventory taken at the ends of 2010 and 2011, Trent's employees failed to count the merchandise in the store's window displays. The cost of this merchandise amounted to \(\$ 13,000\) at the end of 2010 and \(\$ 19,000\) at the end of 2011. As a result of these errors, the cost of goods sold for 2011 will be:

a. Understated by \(\$ 19,000\).

b. Overstated by \(\$ 6,000\).

c. Understated by \(\$ 6,000\).

d. None of the above.