Statement-$I$: Teeth of cartilaginous fishes are modified placoid scales which are backwardly directed.
Statement-$II$: Jaws of cartilaginous fishes are very powerful.

• A
  Statement $I$ and statement $II$ both are correct
• B
  Statement $I$ is correct but statement $II$ is incorrect
• C
  Statement $I$ and statement $II$ both are incorrect
• D
  Statement $I$ is incorrect but statement $II$ is correct