Answer
See answer.
Work Step by Step
Charge must be conserved, so a neutron cannot simply change into a proton via a strong nuclear interaction. When the neutron decays, it produces a proton, an electron, and an antineutrino. Though neutrons and protons are strongly interacting, as discussed on page 930, electrons and neutrinos are leptons, and do not interact via the strong nuclear force.
In particular, the antineutrino must be the product of a decay mediated by the weak interaction.
