What is the dispersion medium in ink?
a.) Solid
b.) Liquid
c.) Gas
d.) None of these

Hint: Dispersion medium is that substance, on which another substance (dispersed phase) is dispersed or spread on it. Such colloids are also known as Sols.

Complete step by step solution:
A colloid is a heterogeneous system in which one substance is dispersed as very fine particles in another substance called dispersion medium.
Ink is a colloidal mixture of dye and water. Here, dye is the dispersed phase in solid form and water is the dispersion medium in liquid form.
Size of the colloidal particles varies from 1 – 1000 nm.
Ink is solid in liquid type of colloid. That type of colloid is known as sol. Some examples of solid in liquid type of sol are paints, cell fluids.

So, the correct answer is “Option B”.

Additional Information:
Here are some types of colloidal systems on the basis of physical properties of dispersed phase and dispersion medium.



Note:
Dispersion medium is present only in colloids. It is not present in solutions. This is because of the particle size of the constituents. In a true solution the particle size is extremely small whereas in colloids particle size ranges from 1 nanometer to 1 micrometer. Because of the bigger size of particles, dispersion medium should not be confused with the solvent of the solution.