$(b)$ Complete neutralization of strong acid and strong base, $pH = 7$.
$(c)$ Hydrolysis of the salt $CH_3COOK, pH > 7$ (salt of weak acid with strong base)
$(d)$ Hydrolysis of the salt $NH_4NO_3, pH < 7$ (salt of strong acid with weak base)
$(K_w = 10^{-14})$