If $M_o$ is the mass of an oxygen isotope $_8O^{17}, M_p$ and $M_n$ are the masses of a proton and a neutron respectively, the nuclear binding energy of the isotope is :

Question

( A ) $(M_o - 8M_p)c^2$
( B ) $M_oc^2$
( C ) $(M_o - 8M_p - 9M_n) c^2$
( D ) $(M_o -17M_n)c^2$