In terms of resistance R and time T, the dimensions of ratio $$\frac{\mu}{\varepsilon}$$ of the permeability $$\mu$$ and permittivity $$\varepsilon$$ is:

A

$$[RT^{-2}]$$

B

$$[R^2T^{-1}]$$

C

$$[R^2]$$

D

$$[R^2T^2]$$