The $INCORRECT$ statement$(s)$ about heavy water is (are):
$(A)$ Used as a moderator in nuclear reactor.
$(B)$ Obtained as a by-product in fertilizer industry.
$(C)$ Used for the study of reaction mechanism.
$(D)$ Has a higher dielectric constant than water.
Choose the correct answer from the options given below:

• A
  $(B)$ only
• B
  $(C)$ only
• C
  $(D)$ only
• D
  $(B)$ and $(D)$ only