The neutron separation energy is defined to be the energy required to remove a neutron from a nucleus. Obtain the neutron separation energy of the nuclei $_{20}Ca ^{41}$ from the following data :$_{13} Al ^{27} \to _{13}Al^{26}+_0 n^1$

Question

$\begin{array}{1 1} 12.89\;Mev \\ 12.3\;Mev \\ 11.56 \;Mev \\ 67.58\;Mev \end{array} $