Energetically, a Fusion Reaction Can Be Self- Sustaining Whenever

Energetically, a fusion reaction can be self- sustaining whenever

A) the reaction proceeds from lower to higher energies on the nuclear energy curve.
B) the reaction proceeds from higher to lower energies on the nuclear energy curve.
C) the reaction proceeds from lighter nuclei to heavier nuclei on the nuclear energy curve.
D) the reaction proceeds from heavier to lighter nuclei on the nuclear energy curve.
E) the reaction obeys the principle of conservation of total energy.