Which of the following is a common unit of comparison used in valuing land?

The common unit of comparison used in valuing land is the acre, particularly when assessing larger parcels of property. An acre is a widely recognized measure in the United States and is equivalent to 43,560 square feet. It is particularly relevant in real estate appraisal because land transactions often involve larger tracts of land rather than smaller areas, making acres a more practical unit compared to yards or meters, which pertain to smaller measurements.

Additionally, the mention of 'section' refers to governmental survey systems where a section typically equals one square mile, or 640 acres. This operational framework helps appraisers compare property sizes in an organized manner, especially in rural or undeveloped areas.

Other units like yards and meters are more commonly used for smaller measurements or in different contexts, such as construction, rather than in land valuation. Heating units are unrelated to land measurement and pertain to energy assessments or systems, making them unsuitable for this specific inquiry. Thus, the acre is the most pertinent and recognized measurement for valuing land within the context of real estate appraisal.