A nucleus $^A_Z X$ has mass represented by $M(A,Z)$. If $M_p$ and $M_n$ denote the mass of proton and neutron respectively and B.E. the binding energy in MeV, then:

Question

( A ) $B.E = [M(A,Z)-ZM_p - (A-Z) M_n]C^2$
( B ) $B.E = [ZM_p + AM_n - M(A, Z)]C^2$
( C ) $B.E = M(A,Z) - ZM_p - (A-Z) M_n$
( D ) $B.E = [ZM_p + (A-Z)M_N - M(A,Z)] C^2$