When a company exchanges machinery and receives a trade-in allowance greater than the book value, this transaction would be recorded with which of the following entries (assuming the exchange was considered to have commercial substance)?

a.debit Machinery and Accumulated Depreciation; credit Machinery, Cash, and Gain on Exchange of Machinery b.debit Cash and Machinery; credit Accumulated Depreciation and Machinery c.debit Machinery and Accumulated Depreciation; credit Machinery and Cash d.debit Cash and Machinery; credit Accumulated Depreciation