Assertion : The quantity $\left(\frac{1}{\sqrt{{\mathrm{\mu }}_0{\mathrm{\epsilon }}_0}}\right)$ is dimensionally equal to velocity and numerically equal to velocity of light.

Reason : ${\mathrm{\mu }}_0$ is permeability of free space and ${\mathrm{\epsilon }}_0$ is the permittivity of free space. 

• A

  If both the assertion and reason are true and reason is a true explanation of the assertion.
   

• B

  If both the assertion and reason are true but the reason is not the correct explanation of assertion.
   

• C

  If the assertion is true but reason is false.
   

• D

  If both the assertion and reason are false.