Answer:
d.miscible
Explanation:
If two liquids are completely miscible, no interfacial tension exists between them.
Interfacial tension is the force of attraction between between the molecules of a fluid that are in contact. This tension forms thick skin at the interface.
In miscible liquids, in which one liquid completely dissolves in another, there is no interfacial tension.
Interfacial tension does not allow miscibility of fluids as the tension between the interface is too great.
So, if two liquids are miscible, there is no interfacial tension between them.