Read the following statements:
Statement $I$: All vertebrates develop a row of vestigial gill slits during the embryonic stage.
Statement $II$: Embryos always pass through the adult stages of other animals.
Which of the following options is correct with reference to these statements?

• A
  Statement $I$ is correct, Statement $II$ is incorrect.
• B
  Statement $I$ is incorrect, Statement $II$ is correct.
• C
  Both Statements $I$ and $II$ are correct.
• D
  Both Statements $I$ and $II$ are incorrect.