David acquired an automobile for 30,000 for use in his unincorporated business at the beginning of 2015 and used the standard mileage rate method in 2015. He plans to switch to the actual expense method in 2016. The automobile was used 25,000 miles in 2015. What is the amount of the adjusted basis of the automobile for purposes of computing depreciation in 2016?

A) 20,000 B) 30,000 C) 15,625 D) 24,000