When both the dispersed phase and the dispersion medium are liquid, the colloid is known as an emulsion.
Correct Answer: Option B - Emulsion
Explanation:
Sol: Solid dispersed in liquid
Gel: Liquid dispersed in solid
Foam: Gas dispersed in liquid
Aerosol: Solid or liquid dispersed in gas
Emulsion: Liquid dispersed in liquid (e.g. milk, mayonnaise)
Hence, the type of colloid is emulsion.