21. On January 1, 2021, Z Corp leased equipment for four years. Lease payments are 40,000 payable at the end of the year. At the end of the lease term, Z Corp has the option to buy the equipment for an additional payment of 50,000. The equipment has a useful life of 10 years. Z doesn't not expect to exercise such an option. Implicit interest rate is 8%. How much is the annual depreciation for the equipment? a) 16,923 b) 33,121 c) 28,310 d) 35,723