On January 1, 20X4, Pigg Corporation sold equipment with a book value of $20,000 and a 10-year remaining useful life to its wholly-owned subsidiary, Skittle Corporation, for $30,000. Both Pigg and Skittle use the straight-line depreciation method, assuming no salvage value. On December 31, 20X4, the separate company financial statements held the following balances associated with the equipment: Pigg Skittle Gain on sale of equipment $10,000 Depreciation expense $3,000 Equipment 30,000 Accumulated depreciation 3,000 A working paper entry to consolidate the financial statements of Pigg and Skittle on December 31, 20X4 included a: Select one: a. debit to equipment for $10,000. b. credit to gain on sale of equipment for $10,000 c. debit to accumulated depreciation for $1,000 O d. credit to depreciation expense for $3,000