ANS:D - none of these.

The statement "Rate of crystallization does not depend upon the extent of supersaturation" is incorrect. The rate of crystallization indeed depends on the extent of supersaturation. Supersaturation is a driving force for crystallization. When a solution is supersaturated, it contains more solute than it can normally dissolve at a given temperature. The excess solute is in a metastable state and tends to precipitate out of the solution to form crystals. The degree of supersaturation affects the likelihood and rate of nucleation and crystal growth. Therefore, the correct option is: none of these.