Inside a nucleus, the nuclear forces between proton and proton, proton and neutron, neutron and neutron are $F_{\text{pp}}$, $F_{\text{pn}}$ and $F_{\text{nn}}$ respectively. Then : (A) $F_{\text{pp}} > F_{\text{pn}} > F_{\text{nn}}$ (B) $F_{\text{pn}} > F_{\text{nn}} > F_{\text{pp}}$ (C) $F_{\text{nn}} > F_{\text{pp}} > F_{\text{pn}}$ (D) $F_{\text{pp}} = F_{\text{pn}} = F_{\text{nn}}$