For tax purposes, a 4-unit apartment building purchased in 1992 must be depreciated using which of the following depreciation methods?

The variable method of depreciation is not recognized in standard tax practices for real estate. Depreciation must be systematic and predictable, which the variable method does not provide. This approach could lead to fluctuations in deductions that are not compliant with the IRS regulations for real estate depreciation.

While the accelerated method allows for larger deductions in the earlier years of an asset's life, it is not typically applicable to residential rental properties like a 4-unit apartment building. The IRS mandates the straight-line method for such properties to ensure a level playing field in tax reporting and to prevent significant tax sheltering in the early years.

The term "passive" refers to a category of income, not a method of depreciation. While depreciation may affect passive income calculations, it does not represent a depreciation method itself. Therefore, this choice is irrelevant to the question regarding how the property should be depreciated for tax purposes.