The correct option is A stabilizes an emulsion
In order to prepare stable emulsions, it is important to add a third component known as emulsifier or emulsifying agent in suitable amounts. Several types of emulsifiers are known:
(i) Long chain compounds with polar groups such as soap, sulphonic acid, sulphates, etc.
(ii) Most of the lyophilic colloids also act as emulsifiers such as glue, gelatin, etc.
(iii) Certain insoluble powders as clay, lamp black, etc.
(iv) Soluble substances like iodine also act as emulsifiers.