Answer:
C = They taste sour
Step-by-step explanation:
The option C is correct. Acids are sour in taste.
All other options are incorrect because,
A = they turn litmus paper blue.
It is the property of base.
B = they typically contain an -OH group.
It is the property of base. Bases give hydroxyl ion.
C = They are sour in taste.
It is the property of acid.
Acids gives H⁺ ions.
D = They feel slippery
It is the property of base. Strong bases are slippery and feel slimy.