Assertion : If a heavy nucleus is split into two medium sized parts, each of the nuclei will have more binding energy per nucleon than the original nucleus. Reason : Joining two light nuclei together to give a single nucleus of medium size means more binding energy per nucleon than the two nucleus.

• A

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

  Ifboth 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: 'B'.