Equal volumes of two $AgI$ sols are mixed together. The first sol is obtained by adding $AgNO_3$ to a slight excess of $KI$,and the second sol is obtained by adding $KI$ to a slight excess of $AgNO_3$. What happens when they are mixed?

• A
  The two sols will stabilize each other.
• B
  The sol particles will acquire more electric charge.
• C
  The sols will coagulate each other mutually.
• D
  $A$ true solution will be obtained.