On January 1st, 2023, XYZ Corporation purchased a delivery truck for $50,000. The truck has an estimated useful life of 5 years and a salvage value of $5,000. Calculate: a) Annual depreciation expense using the straight-line method. b) Accumulated depreciation at the end of the third year. c) Book value of the truck at the end of the fourth year. d) Journal entry to record depreciation expense for the first year.