Final answer:
The energy released in β− decay of a neutron depends on the isotope undergoing decay.
Step-by-step explanation:
In β− decay of a neutron, an electron (β− particle) is emitted from the nucleus.
The energy released in this decay varies and depends on the isotope undergoing decay.
Option a) is correct. The energy released can be determined by calculating the mass difference between the parent nucleus and the daughter nucleus, and then converting it into energy using the relationship 1 amu = 931 MeV.