The correct property of bases from your options is "feels slippery." Bases typically feel slippery or soapy to the touch.
Here’s a quick rundown of the other options:
- "Releases hydrogen ions in water": This describes acids, not bases.
- "pH less than 7": This also describes acids; bases have a pH greater than 7.
- "Sour taste": This is characteristic of acids.
So, "feels slippery" is the property associated with bases.