c
\(\begin{array}{l}
Dimension\,of\,\sqrt {\frac{{{\varepsilon _0}}}{{{\mu _0}}}} \\
\left[ {{\varepsilon _0}} \right] = \left[ {{M^{ - 1}}{L^{ - 3}}{T^4}{A^2}} \right]\\
\left[ {{\mu _0}} \right] = \left[ {ML{T^{ - 2}}{A^{ - 2}}} \right]\\
Dimension\,of\,\,\sqrt {\frac{{{\varepsilon _0}}}{{{\mu _0}}}}  = {\left[ {\frac{{{M^{ - 1}}{L^{ - 3}}{T^4}{A^2}}}{{ML{T^{ - 2}}{A^{ - 2}}}}} \right]^{\frac{1}{2}}}\\
 = {\left[ {{M^{ - 2}}{L^{ - 4}}{T^6}{A^4}} \right]^{1/2}}\\
 = \left[ {{M^{ - 1}}{L^{ - 2}}{T^3}{A^2}} \right]
\end{array}\)