Figure 13 is a plot of binding energy per nucleon Eb, against the nuclear
mass M; A, B, C, d, E, F correspond to different nuclei. Consider four reactions:
(i) A + B → C + ε (ii) C → A + B + ε
(iii) D + E → F + ε (iv) F → D + E + ε
where ε is the energy released.
In which reactions is ε positive?