Fusion Questions

The above is a plot of binding energy per nucleon $E_b$, against the nuclear mass $M$; $A,B,C,D,E,F$ correspond to different nuclei. Consider four reactions:(i) $A+B\to C+\epsilon$ (ii) $C\to A+B+\epsilon$ (iii) $D+E\to F+\epsilon$ (iv) $F\to D+E+\epsilon$ where $\epsilon$ is the energy released. In which reactions is $\epsilon$ positive?