A: Colloids scatter light while true solutions do not.

R: The particles in the colloidal sol move much slower than that of the true solution.

Given data: To find whether the colloids scatter light while true solutions do not. And also find whether the particles in the colloidal sol move much slower than that of the true solution 

Detailed solution:

A true solution does not exhibit the Tyndall effect (light scattering), a colloidal solution does

This has nothing to do with the particles' slower motion than in a true solution

The Tyndall effect occurs when the colloid's particles are large enough to scatter a light beam, making its path visible

Hence, the correct option is B.