Brownian movement is more pronounced for smaller particles than for bigger-particles. The speed of moving particles is inversely proportional to the size of the particles. Higher is the size, lower is the speed.
Thus, option A is correct.
Lyophobic sols- The colloidal system in which the particles of the dispersed phase have no or very little interactions with the dispersion medium are called lyophobic sols. For example Fe(OH)3 and metal sulphides like As2S3 .
Thus, option B is incorrect.
Hardy-Schulze law states that higher the charge of the coagulating ions, greater its coagulating power, having opposite sign of solution. This law takes into consideration only the charge carried by an ion, not its size.
Thus, option C is incorrect.
Easily liquefiable gases are readily adsorbed than gases which do not liquefy easily. Easily liquefiable gases have higher critical temperature and stronger Vander Waals forces of attraction.
Thus, option D is incorrect.