The acceleration of electron in the first orbit of hydrogen atom is

• A

  $\frac{4{\mathrm{\pi }}^2\mathrm{m}}{{\mathrm{h}}^3}$

• B

  $\frac{{\mathrm{h}}^2}{4{\mathrm{\pi }}^2\mathrm{mr}}$

• C

  $\frac{{\mathrm{h}}^2}{4{\mathrm{\pi }}^2{\mathrm{m}}^2{\mathrm{r}}^3}$

• D

  $\frac{{\mathrm{m}}^2{\mathrm{h}}^2}{4{\mathrm{\pi }}^2{\mathrm{r}}^3}$