Final answer:
The property that makes water such a good solvent is its polarity, enabling it to dissolve many substances through the formation of hydrogen bonds.
Step-by-step explanation:
Water is often referred to as the universal solvent because it has the ability to dissolve many substances. This characteristic is attributed to water's polarity. The property of water that makes it such a good solvent is its polarity, due to the partial negative charge on its oxygen atom and partial positive charges on its hydrogen atoms. This polarity allows water molecules to form hydrogen bonds with other polar molecules or ions, which enables these substances to dissolve within the water. Hence, the correct answer to the question is C. Polarity.