Why option B is not correct and why option D is correct

On January 1, 2016, P Corporation sold equipment with a 3-year remaining life and a book value of $40,000 to its 70% owned subsidiary for a price of $46,000. In the consolidated workpapers for the year ended December 31, 2017, an elimination entry for this transaction will include a: a) debit to Equipment for $6,000. b) debit to Gain on Sale of Equipment for $6,000. c) credit to Depreciation Expense for $6,000. d) debit to Accumulated Depreciation for $4,000. Answer: d