Density of ice is $\rho$ and that of water is $\sigma$. What will be the decrease in volume when a mass M of ice melts ?

• A

  $\frac{\mathrm{M}}{(\mathrm{\sigma }-\mathrm{\rho })}$

• B

  $\frac{\mathrm{\sigma }-\mathrm{\rho }}{\mathrm{M}}$

• C

  $\mathrm{M}\left[\frac{1}{\mathrm{\rho }}-\frac{1}{\mathrm{\sigma }}\right]$

• D

  $\frac{1}{\mathrm{M}}\left[\frac{1}{\mathrm{\rho }}-\frac{1}{\mathrm{\sigma }}\right]$