Tritium is an isotope of hydrogen whose nucleus Triton contains 2

Tritium is an isotope of hydrogen whose nucleus Triton contains 2 neutrons and 1 proton. Free neutrons decay into $P+\overline{e}+\overline{\upsilon }$ . If one of the neutrons in Triton decays, it would transform into He3 nucleus. This does not happen. This is because

(a) Triton energy is less than that of a He3 nucleus

(b) the electron created in the beta decay process cannot remain in the nucleus

(c) both the neutrons in triton have to decay simultaneously resulting in a nucleus with 3 protons, which is not a He3 nucleus

(d) because free neutrons decay due to external perturbations which is absent in a triton nucleus