ANS:A - colloidal state from those present in the true solutions.

Colloidal State: Colloids are a type of mixture where one substance (the dispersed phase) is finely distributed within another substance (the continuous phase). In colloidal solutions, the dispersed particles are typically larger than individual molecules but smaller than particles in suspensions. These dispersed particles can be solids, liquids, or gases. Examples of colloids include milk, fog, gelatin, and paint.

1. True Solutions: True solutions are homogeneous mixtures where one substance (the solute) is completely dissolved in another substance (the solvent) at the molecular level. In true solutions, the solute particles are very small and evenly distributed throughout the solvent. Examples of true solutions include saltwater, sugar dissolved in water, and air (a mixture of gases).

Now, in the context of dialysis: Dialysis is a process used to separate substances based on differences in their molecular sizes or properties. When we refer to dialysis separating substances in the colloidal state from those present in the true solutions, it means that dialysis can effectively separate larger colloidal particles from smaller solute molecules dissolved in the solvent. For example, let's consider a scenario where we have a mixture containing colloidal particles (such as proteins) and solute molecules dissolved in a solvent (such as water). When this mixture is subjected to dialysis, the semipermeable membrane used in dialysis allows smaller solute molecules (from the true solution) to pass through while blocking larger colloidal particles. As a result, the colloidal particles are retained on one side of the membrane, while the solute molecules pass through to the other side, effectively separating the colloidal substances from those present in the true solutions.