In solar radiation, the intensity of radiation is maximum around the wavelength $\lambda$ .  If R is the radius of the sun and c is the velocity of light, the mass lost by the sun per second is proportional to     

• A

  $\frac{{\mathrm{R}}^2}{{\mathrm{\lambda }}^4{\mathrm{c}}^2}$

• B

  $\frac{{\mathrm{R}}^2}{{\mathrm{\lambda }}^2{\mathrm{c}}^2}$

• C

  $\frac{{\mathrm{R}}^3}{{\mathrm{\lambda }}^4{\mathrm{c}}^3}$

• D

  $\frac{{\mathrm{R}}^3}{{\mathrm{\lambda }}^4{\mathrm{c}}^2}$