a
\(\begin{array}{l}
impedance\,is\,same\,as\,{\rm{resistance}}\,but\,in\,ac\,circuit\\
\therefore \,Dimension\,of\,impedance\\
= \frac{{dimension\,of\,voltage}}{{dimension\,of\,current\,}}\\
\frac{{\left[ V \right]}}{{\left[ T \right]}} = \frac{{\left[ {M{L^2}{T^{ - 3}}{I^{ - 1}}} \right]}}{I} = \left[ {M{L^2}{T^{ - 3}}{I^{ - 2}}} \right]
\end{array}\)