Explain two methods of Purification of colloids

Question

$\begin{array}{1 1} \text{(a) Distillation n Separation by magnets} \\ \text{(b)Dialysis , Ultrafiltration} \\ \text{(c) Fractional Distillation , Electro dialysis} \\ \text{(d)Ultracentrifugation , Dialysis} \end{array}$