Introduction:
When a crystal of the solute is introduced into a super saturated solution of the solute, there are several possible outcomes. In this case, the correct answer is option 'B', which states that the excess solute crystallizes out. Let's explore why this is the correct answer in detail.

Explanation:
When a solution is super saturated, it means that it contains more solute than it can normally hold at a given temperature. This is achieved by dissolving the solute in a solvent at a higher temperature and then cooling the solution down. As a result, the solute remains dissolved even though it would normally crystallize out at that temperature.

Introduction of a Crystal:
When a crystal of the solute is introduced into the super saturated solution, several processes can occur:

Nucleation:
The introduction of a solute crystal provides a surface for the solute molecules to attach to. This leads to the formation of small solute particles around the crystal, a process known as nucleation.

Crystal Growth:
Once nucleation occurs, the solute particles can continue to grow by attracting more solute molecules from the surrounding solution. This leads to the growth of the crystal.

Excess Solute Crystallization:
As the crystal continues to grow, it absorbs solute molecules from the solution, reducing the concentration of the solute in the solution. Eventually, the concentration of the solute in the solution becomes lower than its saturation point at that temperature, causing the excess solute to crystallize out.

Equilibrium:
Once the excess solute has crystallized out, the solution reaches a state of equilibrium where the rate of dissolution of solute crystals is equal to the rate of crystallization of excess solute.

Conclusion:
In summary, when a crystal of the solute is introduced into a super saturated solution of the solute, the excess solute crystallizes out. This occurs through nucleation, crystal growth, and the reduction of solute concentration in the solution. The remaining solution reaches a state of equilibrium where the rate of dissolution is balanced by the rate of crystallization.