David acquired an automobile for $30,000 for use in his unincorporated business at the beginning of 2016 and used the standard mileage rate method in 2016. He plans to switch to the actual expense method for 2017. The automobile was used 25,000 miles in 2016. What is the amount of the adjusted basis of the automobile for purposes of computing depreciation in 2017?
◦ $30,000
◦ $15,625
◦ $24,000
◦ $20,000