In which of the following situations does a taxpayer have to recapture the depreciation deduction (meaning he or she includes in income part or all of the depreciation he or she deducted in previous years)?

a) If his or her business use of listed property falls to 50% or less in a tax year after the tax year he or she placed the property in service

b) If he or she takes a Section 179 deduction for an asset and before the end of the asset's recovery period the percentage of business use drops to 50% or less

c) If he or she sells or exchanges depreciable property at a gain

d) All of the above