Answer the question on basis of passage given below :
Lyophobic sols like those of metals (Au, Ag, etc) are unstable and are easily precipitated by addition of electrolytes. However, it is observed that the addition of certain lyophilic colloids like gums, soaps, gelatine, etc. to lyophobic colloids (like a metal sol) render lyophobic colloids difficult to coagulate by the addition of electrolytes. The process is known as 'protection' and the lyophilic colloids are termed as Protective colloids. It is believed that the protective action of the lyophilic colloids is due to the covering up of the particles of the lyophobic colloid by those of the lyophilic colloid.
Evidently, smaller the gold number of a protective colloid, the greater is its protective action. In which of the following sols, the colloidal particles will move towards the cathode during electrophoresis?

1. A \(Fe ( OH )_3\) sol
2. B Au sol
3. C Starch sol
4. D \(As _2 S_3\) sol