What characteristic distinguishes masonry products?

The correct choice highlights that masonry products must be installed by masons, who are skilled tradespeople trained specifically in the techniques and practices of masonry work. This distinguishes masonry from other construction materials because the installation process requires expertise to ensure structural integrity and proper alignment. Masons understand how to properly mix mortar, lay bricks, blocks, or stone, and create stable structures, which is essential for safety and longevity in masonry applications.

The other options do not accurately reflect the distinguishing characteristics of masonry products. For instance, masonry materials, such as bricks and concrete blocks, can be heavy, and frequently heavier than wood. Also, masonry products typically do not include organic materials; rather, they are primarily mineral-based. While many masonry products do involve concrete, not all masonry products are solely concrete-based, as they can also include clay, brick, and stone, each of which has unique properties and uses. Therefore, the requirement for skilled masons to install these products is what truly sets masonry apart in the construction field.