Assertion : In a pedigree analysis, represents five unaffected offsprings. Reason: In a pedigree analysis, the offsprings are numbered with arabic numerals $(1,2,3 \ldots .$. and a generation is numbered with roman numerals (I, II, III...).

• A

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