The correct property of bases from the options provided is "feels slippery." Bases typically feel slippery to the touch.
To clarify the other options:
- "Sour taste" is a property of acids, not bases.
- "Releases hydrogen ions in water" is also a property of acids. Bases typically produce hydroxide ions (OH⁻) when dissolved in water.
- "pH less than 7" is again a property of acids; bases have a pH greater than 7.
Therefore, the only property listed that is characteristic of bases is that they "feel slippery."