Given below are two statements:
Statement $I$: $A$ time-varying electric field is a source of a changing magnetic field and vice-versa. Thus,a disturbance in an electric or magnetic field creates $EM$ waves.
Statement $II$: In a material medium,the $EM$ wave travels with speed $v = \frac{1}{\sqrt{\mu_{0} \varepsilon_{0}}}$.
In the light of the above statements,choose the correct answer from the options given below:

• A
  Both statement $I$ and statement $II$ are true.
• B
  Both statement $I$ and statement $II$ are false.
• C
  Statement $I$ is correct but statement $II$ is false.
• D
  Statement $I$ is incorrect but statement $II$ is true.