Gardner Corporation purchased a truck at the beginning of 2012 for $90,000. The truck is estimated to have a salvage value of $3,600 and a useful life of 120,000 miles. It was driven 18,000 miles in 2012 and 32,000 miles in 2013. What is the depreciation expense for 2013?
A) $36,000
B) $24,000
C) $38,400
D) $23,040