Answer
(c) a neutron with a total energy of 1500MeV
Work Step by Step
The rest energy of a particle is :-
$E_{0}=mc^{2}$
Thus the rest energy is independent of the total energy. It depends only on the mass(m) of the particle.
The more the mass, more is its rest energy.
Mass of electron $=9.1\times10^{-31}kg$ and its rest energy $E_{0}=0.511MeV$
Mass of proton $=1.67\times10^{-27}kg$ and its rest energy $E_{0}=938MeV$
Mass of neutron $=1.67\times10^{-27}kg$ and its rest energy $E_{0}=939MeV$
So the rest energy of neutron is more compared to proton and electron. (c)
