Assertion : Sound waves cannot travel in vacuum but light can travel in vacuum. Reason : Sound waves are longitudinal waves and they cannot be polarised but electromagnetic waves are transverse and they can be polarised.

• 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'.