Which of the following correctly illustrates the concept of solvency in biology?

The concept of solvency in biology refers specifically to the ability of a solvent, such as water, to dissolve a variety of substances. This is crucial in biological systems because many biological reactions occur in aqueous solutions, where water acts as the solvent. For example, when cells take up nutrients or expel waste, these processes rely on the solvent properties of water to facilitate the movement and mixing of different substances.

When considering the other options, the capacity for substances to adhere to each other relates more to adhesion or cohesion rather than solvency. Maintaining homeostasis pertains to the regulation of internal conditions within an organism, which may involve various factors including but not limited to solvent interactions. The tendency of water to resist temperature changes describes its high specific heat capacity, not solvency. Thus, the ability to dissolve various substances is the most accurate representation of solvency in a biological context.