The correct option is C Filter paper but not through animal membrane
The colloidal state can be regarded as the intermediate state between molecules and particles of a coarse suspension.
They diffuse very slowly in solution and can not pass through animal or vegetable membranes. For example: starch, gelatin, silicic acid, proteins etc. This class of substances generally exist in amorphous or gelatinous condition. Hence, the name colloid means "glue form".