Please explain the answer

20. a. A truck was purchased on July 1 for $20,000. The estimated salvage value is $2,000. The estimated useful life is 3 years. Using straight-line method of depreciation, the amount of depreciation in the adjusting entry at fiscal year-end on December 31 is: Depreciation Expense Truck $555.56 Accumulated Depreciation-Truck $555.56 b. Accumulated Depreciation-Truck $1,500 Depreciation Expense- Truck $1,500 Depreciation Expense- Truck $500 Accumulated Depreciation-Truck $500 d. Depreciation Expense- Truck $3,000 Accumulated Depreciation-Truck 3,000 c