Given the masses of various atomic particles
m
p
= 1.0072 u, m
n
= 1.0087 u, m
e
= 0.000548 u,
${m_{\overline v }} = 0, m
d
= 2.0141 u, where p \equiv proton,
n \equiv neutron,
e \equiv electron, \overline v \equiv antineutrino and
d \equiv $ deuteron. Which of the following process is
allowed by momentum and energy
conservation?