21. ABC Company intends to put $3,000 into its savings account at the beginning of every six months for the next five years. The savings account earns 6% interest compounded semi-annually. The amount of interest that ABC Company will have earned at the end of the five years is closest to: A. $4,392 B. $5,851 C. $6,456 D. $3,822 E. $5,424 ABC Company purchased a building on January 1,2025 at a cost of $230,000. ABC estimated that the building would have a useful life of 10 years and a residual value of $10,000. Assuming ABC Company employs the sum-of-the-years'-digits depreciation method and the balance in the accumulated deprecia account is $136,000, how long has this building been in use? A. 5 years B. 4 years C. 3 years D. 2 years E. unable to determine from the information given