What is the correct answer?

4

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

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

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

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