To determine the estimated reproduction cost of a subject building using the index method, the appraiser multiples the index factor by which of the following?

The estimated reproduction cost of a subject building using the index method is calculated by multiplying the index factor by the original construction cost of the building. The index method adjusts historical construction costs to reflect current prices, offering a way to estimate the current cost required to reproduce an exact replica of the building.

This approach relies on historical data related to construction costs, where the original construction cost serves as the baseline. By applying the index factor, which accounts for changes in materials, labor, and overall economic conditions since the original construction, appraisers can arrive at a current estimate that reflects today's economic situation.

The other choices do not provide the foundational data necessary for this calculation. The market value estimate refers to what the property could sell for in the current market, the replacement cost estimate aims at what it would cost to replace the building with one of similar utility, and the current market rate pertains to various market metrics, none of which align with the original cost foundation needed for the index method.