Two deuterium nuclei each of mass m, fuse together to form a helium nucleus , releasing an energy E. If C is the velocity of light , the mass of helium nucleus formed will be

Question

$\begin{array}{1 1} 2m+\frac{E}{C^2} \\ \frac{E}{mc^2} \\ m+\frac{E}{C^2} \\ 2m- \frac{E}{c^2} \end{array}$