Which of these is known to promote blood clotting during the embalming process?

Hard water is recognized as a substance that can promote blood clotting during the embalming process. This is primarily due to its mineral content, particularly calcium ions, which can enhance coagulation. Embalmers often consider the quality of water used in the embalming fluid, as hard water can affect the efficacy of the embalming solution and lead to challenges such as increased chances of clotting.

In contrast, water and alcohol do not contribute to the clotting process in the same way. Water, especially in its pure form, is intended to aid in the dilution of embalming fluids, while alcohol tends to act as a solvent and has dehydrating properties that are not associated with blood coagulation. Glycerin, primarily used for its moisturizing properties, works to keep tissues pliable but does not promote clotting. Thus, hard water's mineral profile aligns with the mechanisms that enhance the clotting process in embalming, positioning it as the correct choice in this context.