Lyophobic colloids are:
(A) Reversible
(B) Irreversible
(C) Water loving
(D) Solvent loving

Hint:The mixture in which one substance is distributed in another substance is known as a colloid. One substance is known as the dispersed phase and the other is known as the dispersing phase. The dispersed phase is inseparable after filtering or centrifugation.

Complete answer:We know that a colloid is a mixture in which fine particles are scattered in a dispersion medium. The particles are solid in nature while the dispersion medium is a fluid. If the fluid used as a dispersion medium is water then the colloid is known as hydrosol. If the fluid used as a dispersion medium is air then the colloid is known as aerosol.
We know that lyo means liquid and phobic means hating. Thus, lyophobic colloids are liquid hating colloids.
Lyophobic colloids are the colloidal solutions in which the dispersed phase or the colloidal particles have very less affinity towards the dispersion medium. This means that in lyophobic colloids, the affinity between colloidal particles and liquid molecules is very less.
Lyophobic colloids are unstable in nature. They coagulate easily in addition to a small amount of any suitable electrolyte.
Lyophobic colloids cannot be prepared directly. Thus special methods are used for the preparation of lyophobic colloids
In lyophobic colloids, the colloidal particles cannot be separated from the dispersion medium Thus, lyophobic colloids are irreversible.
Thus, lyophobic colloids are irreversible.

Thus, the correct option is (B) irreversible.

Note:We know that lyophobic colloids are liquid hating colloids. When we mix lyophobic colloids with liquid the forces of attraction between colloidal particles are very weak. And thus, the liquid system does not pass into a colloidal state very easily. In lyophobic colloids, the charge on the colloidal particles is the same throughout the solution. Lyophobic colloids show low colligative properties.