The purification of colloids is carried out by which of the following processes?

Various types of colloids are given below. Match Column $X$ with Column $Y$.

$X$ (Colloid)	$Y$ (Classification)
$I$. Smoke	$A$. Sol
$II$. Gelatin	$B$. Aerosol
$III$. Soap lather	$C$. Emulsion
$IV$. Milk	$D$. Foam

$X$ is a protecting colloid. The following data is obtained for preventing the coagulation of $10 \ mL$ of gold sol to which $1 \ mL$ of $10 \% NaCl$ is added. What is the gold number of '$X$'?

Expt. No.	Weight of $X$ (in $mg$) added to gold sol	Coagulation
$1$	$24$	Not prevented
$2$	$23$	Not prevented
$3$	$26$	prevented
$4$	$27$	prevented
$5$	$25$	prevented

Which of the following is not correct?

Consider the following statements related to colloids.
$(I)$ Lyophobic colloids are not formed by simple mixing of dispersed phase and dispersion medium.
$(II)$ For emulsions,both the dispersed phase and the dispersion medium are liquid.
$(III)$ Micelles are produced by dissolving a surfactant in any solvent at any temperature.
$(IV)$ Tyndall effect can be observed from a colloidal solution with dispersed phase having the same refractive index as that of the dispersion medium.
The option with the correct set of statements is

The properties of a colloidal solution are primarily due to: