If the binding energy per nucleon in ${}_{3}^{7}\mathrm{Li}$ and ${}_{2}^{4}\mathrm{He}$ nuclei are 5.60 MeV and 7.06 MeV respectively, then in the reaction $\mathrm{p} + {}_{3}^{7}\mathrm{Li} \rightarrow 2\,{}_{2}^{4}\mathrm{He}$, the energy of the proton must be\\
(1) 39.2 MeV\\
(2) 28.24 MeV\\
(3) 17.28 MeV\\
(4) 1.46 MeV