Bluenose's year end is December 31. Its financial statements for the years 2021 and 2020 contained an error as follows: 2021 2020 Ending inventory $4,000 overstated $6,000 overstated Depreciation expense $12,000 understated $24,000 overstated Assume that no correcting entries were made at December 31, 2020. Ignoring income taxes, by how much will retained earnings at December 31, 2021 be overstated or understated? Show your work. (4 marks) a. $8,000 understated b. $12,000 overstated C. $12,000 understated d. $30,000 understated