Tyndall effect is more effectively shown by:

The Tyndall effect is the phenomenon in which a beam of light becomes visible when it passes through a medium containing particles large enough to scatter the light. The necessary condition is that the dispersed particles should have a diameter roughly between $$10^{-7}\,\text{cm}$$ and $$10^{-5}\,\text{cm}$$ so that they can scatter visible radiation. If the particles are much smaller than this range, no appreciable scattering occurs, while if they are much larger, the medium ceases to be optically homogeneous and the beam gets blocked instead of only being scattered.

Now, let us examine each of the given dispersions in the light of this particle-size criterion.

We have a true solution: in a true solution the solute particles have dimensions typically less than $$10^{-8}\,\text{cm}$$. Because these particles are far smaller than the wavelength of visible light, they do not scatter light to any observable extent. So, a true solution does not exhibit the Tyndall effect.

Next, consider a suspension: in a suspension the particles are usually larger than $$10^{-5}\,\text{cm}$$. Such coarse particles block or absorb light instead of merely scattering it, so the passage of a narrow beam cannot be seen as a luminous path. Therefore, a suspension is also unsuited for showing the Tyndall effect.

Now we look at lyophilic colloids: in a lyophilic (solvent-loving) colloid, although the particle size is in the proper colloidal range, the dispersed particles are surrounded by thick layers of the solvent. This sheath diminishes the difference between the refractive indices of the dispersed phase and the dispersion medium, and light scattering depends directly on this refractive-index contrast. Because of the reduced contrast, a lyophilic colloid shows the Tyndall effect only weakly.

Lastly, consider lyophobic colloids: in a lyophobic (solvent-hating) colloid the particles lie squarely in the colloidal size range, and they do not carry thick solvent layers. Hence the refractive-index difference between the dispersed particles and the medium remains large, giving rise to strong scattering. Consequently, the luminous path of a light beam becomes very bright and distinct; in other words, the Tyndall effect is displayed most effectively by a lyophobic colloid.

Comparing all four cases, we find that the maximum light scattering, and hence the most prominent Tyndall effect, occurs for the lyophobic colloid.

Hence, the correct answer is Option C.