The speed of an electron in the innermost orbit of the hydrogen atom (Bohr radius = 52.9 pm, $\left.m_{\mathrm{e}}=9.11\times {10}^{-31}\mathrm{kg}\right)$ is

The required speed is

$$\begin{gathered} v=\frac{2\pi }{h}\left(\frac{e^2}{4\pi {\epsilon }_0}\right) \\ =\frac{2\left(3.14\right)}{\left(6.626\times {10}^{-34}\mathrm{Js}\right)}\left[\frac{{\left(1.602\times {10}^{-19}\mathrm{C}\right)}^2}{1.112\times {10}^{-10}{\mathrm{C}}^2{\mathrm{N}}^{-1}{\mathrm{m}}^{-2}}\right] \\ =2.19\times {10}^6{\mathrm{ms}}^{-1} \end{gathered}$$

The option B is correct.