Hi sir, can you give me explaination for this question? thank you so much!

A company acquires a fixed asset for $48,000. The asset has a useful life of 10 years and a salvage value of $3,000. What is the book value of the asset at the end of the fourth year if the company uses the straight-line method? O $28,800 O $30,000 O $27,000 O $25,800