Insoluble impurities from solution during crystallization are removed by :
A.Drying
B.Filtration
C.Heating
D.Cooling

Hint: In the given question we have to find out about each of the processes and what changes it embarks on the substances it is allowed to deal with. Now after that when we get the data we see that the process which we are looking for is the Filtration, it is the process in which the is the separation of small particles of solid matter from a liquid

Complete step by step solution:
So in the question it has been asked the process of the separation which will be used for the process of clarification of the insoluble impurities.
Here the given options are
a)Drying
b)Filtration
c)Heating
d)Cooling
Now we have to go through the given options one by one to obtain the right answer.
Heating: Heating is the process in which there is an increase in the temperature of a body from its initial or original temperature.
Cooling: Cooling is among the processes in which there is a decrease in the temperature of a body from its original temperature.
Filtration: Filtration is the process in which the separation of small particles of solid matter from a liquid. This is done by causing the liquid in order to pass through the pores of some substance. This substance is called a filter.
Drying: Drying is the process in which there is drying up of the liquid which is present on the material. This is done by heating the material.

So, the correct option would be option B.

Note: Crystallization or crystallisation is the process by which a solid forms, where the atoms or molecules are highly organized into a structure known as a crystal. Some of the ways by which crystals form are precipitating from a solution, freezing, or more rarely deposition directly from a gas.