Tyndall effect in colloidal solution is due:
A. Absorption of light
B. Scattering of light
C. Reflection of light
D. Presence of electrically charged particles

Hint :Through a very fine suspension when a light gets passed the scattering of light takes place due to collision. This effect is known as tyndall effect. To determine the size and density of particles in aerosols and other colloidal matter, tyndall effect is used in nephelometers.

Complete Step By Step Answer:
Colloidal solution is a mixture in which the particles of solutions are suspended in the fluid regularly. Some examples of colloidal solution are gelatin, muddy water, butter, blood, colored glass and so on.
Milk is also an example of colloidal solution because it is a homogeneous mixture and the particles of milk do not settle down when left undisturbed.
In colloidal solution, when scattering of light takes place the scattering is due to collision of light rays to the very fine suspension particles of colloidal solution. This effect is called the tyndall effect. Tyndall effect is also known as tyndall scattering.
So, option B is correct.

Note :
Tyndall scattering is similar to Rayleigh scattering. Rayleigh scattering is defined by a mathematical formula but there is a condition that the light-scattering particles should be far smaller than the wavelength of the light. For a dispersion of particles in Rayleigh formula, the particle sizes must be below roughly forty nanometres (for visible light), and the particles may be individual molecules. Colloidal particles are bigger, and are in the rough vicinity of the size of a wavelength of light. Tyndall scattering is much more intense than Rayleigh scattering because of the bigger particle sizes involved.