Assertion: Molal elevation constant depends on the nature of the solvent. Reason: Molal elevation constant is the elevation in boiling point when 1mole of the solute is dissolved in 1kg of solvent.(A) Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.(B) Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.(C) Assertion is correct but Reason is incorrect.(D) Both Assertion and Reason are incorrect.

The assertion is correct, but the reason is incorrect.

The molal elevation constant, often denoted as Kf, is a constant for a given solvent and is independent of the nature of the solute. It is defined as the elevation in boiling point when 1 mole of a non-volatile solute is dissolved in 1 kg of solvent. However, it is not dependent on the nature of the solvent; it is a property of the solvent-solute system. Therefore, the assertion is correct in stating that the molal elevation constant depends on the nature of the solvent, but the reason given is incorrect because it misrepresents the concept of the molal elevation constant.

So, the correct answer is (C) Assertion is correct, but Reason is incorrect.