XYZ company using the periodic inventory method correctly recorded a December 29 purchase of merchandise, but the merchandise was not included in the physical inventory count on December 31 (end of the accounting period). The error caused an:

a) overstatement of both income and assets by the same amount.

b) overstatement of inventory, purchases, and accounts payable.

c) understatement of inventory, purchases, and accounts payable.

d) understatement of both income and assets by the same amount.