Which of these is a key factor in determining market value?

The determination of market value is primarily influenced by the prices of comparable properties, also known as "comps," in the current market. This approach rests on the fundamental principle of real estate appraisal that values are established based on what similar properties sell for in a given area. By analyzing recent sales data from properties with similar characteristics—such as location, size, condition, and amenities—appraisers can establish a fair market value for the subject property.

Current market prices for comparable properties reflect the demand and supply dynamics of the real estate market, offering insights into what buyers are willing to pay. This makes option C the key factor since it provides a factual basis for valuation rather than relying on more subjective elements or outdated data.

Historical price trends, while informative, do not necessarily reflect the current market conditions, as they may be affected by a variety of external economic factors over time. The financial conditions of the buyer are indeed significant, but they do not directly influence the objective market value of a property; rather, they affect the buyer's ability to purchase. Lastly, the emotional attachment of the seller can skew their perception of value but does not contribute to the market’s reality, as market value is determined by external market conditions rather than personal feelings.