In which of the following, the identity of initial substance remains unchanged?(a) Curdling of milk(b) Formation of crystals by process of crystallization(c) Fermentation of grapes(d) Digestion of food

Correct Answer: (b) Formation of crystals by process of crystallization

Explanation: In the formation of crystals by the process of crystallization, the composition of the initial substance does not change but it merely gets crystallized.