Fill in the blank. Savannah purchased a machine in 2018 and claimed a Section 179 expense deduction on the total purchase price. In 2021, business use dropped below 50%. As a result of this drop, Savannah must __________.

A,Continue to use the same depreciation method and basis.

B,Change to a straight-line method. MACRS is not allowed.

C,Complete a calculation to determine the amount of recapture to report as ordinary income for this tax year, and she will need to increase her adjusted basis in the asset accordingly.

D.Stop taking depreciation on the machine.