Which of the following is a property of bases?

Bases are defined by their ability to accept protons or donate electron pairs in chemical reactions. One of the defining properties of bases is that they release hydroxide ions (OH-) when dissolved in water, which increases the solution's pH, making it more alkaline. This characteristic of liberating OH- ions is fundamental to the behavior of bases in various chemical reactions and in interactions with acids.

The other options do not describe properties of bases accurately. For instance, tasting sour is indicative of acids, not bases. The action of dissolving metals is commonly associated with acids, which can react with certain metals to produce hydrogen gas. Lastly, turning blue litmus paper red is a characteristic of acids; bases typically turn red litmus paper blue. Therefore, the option about liberating OH- in solution is the only one that correctly outlines a property of bases.