The strong nuclear force between a neutron and a proton in a zero orbital angular momentum state is denoted by F_np(r), where r is the separation between them. Similarly, F_nn(r) and F_pp(r) denote the forces between a pair of neutrons and protons, respectively, in a zero orbital angular momentum state. Which of the following is true on average if the inter-nucleon distance is 0.2 fm < r < 2 fm?