A quantity $$\alpha$$ is defined as $$\alpha = \frac{e^2}{4\pi\varepsilon_0 c \hbar}$$, where $$e$$ is electric charge, $$\hbar = \frac{h}{2\pi}$$ is the reduced Planck's constant and $$c$$ is the speed of light. The dimensions of $$\alpha$$ are

A

$$[M^0 L^0 T^0 I^0]$$

B

$$[M^1 L^{-1} T^2 I^{-2}]$$

C

$$[M^2 L^1 T^{-1} I^0]$$

D

$$[M^0 L^3 T^1 I^{-2}]$$