Cullumber Corporation purchased a patent for $153000 on September 1, 2016. It had a useful life of 10 years. On January 1, 2018, Cullumber spent $45000 to successfully defend the patent in a lawsuit. Cullumber feels that as of that date, the remaining useful life is 5 years. What amount should be reported for patent amortization expense for 2018?

$36540.

$33480.

$35520.

$26520.