Preparation of Lyophobic sols by chemical method involves

Which of the following is most active in coagulating $Fe(OH)_3$ sol,if the sol is made by hydrolysis of $FeCl_3$?

Sodium lauryl sulphate is an example of:

The emulsifying agent in milk is

The correct statement$(s)$ related to colloids is(are):
$(A)$ The process of precipitating colloidal sol by an electrolyte is called peptization.
$(B)$ Colloidal solution freezes at a higher temperature than the true solution at the same concentration.
$(C)$ Surfactants form micelles above the critical micelle concentration $(CMC)$. $CMC$ depends on temperature.
$(D)$ Micelles are macromolecular colloids.

Which of the following properties is responsible for the development of colour in colloids?