Statement I: Common ion effect is defined as a shift in equilibrium on adding a substance that provides more of an ionic species already present in the dissociation equilibrium.
Statement II:  Common ion effect is a phenomenon  which can be explained on the basis of  Le-Chatelier's principle.

• A

  Both statements I and II are correct.

• B

  Statement I is correct and statement II is incorrect.

• C

  Statement I is incorrect and statement II is correct.

• D

  Both statements I and II are incorrect.