Assertion : $\mathrm{Ce}^{4+}$ is used as an oxidising agent in volumetric analysis.Reason : $\mathrm{Ce}^{4+}$ has the tendency of attaining +3 oxidation state.

• Correct answer
  A

  If both assertion and reason are true and reason is the correct explanation of assertion
• B

  If both assertion and reason are true but reason is not the correct explanation of assertion
• C

  If assertion is true but reason is false
• D

  If both assertion and reason are false.

Hence, the correct answer is option: 'A'.