(a) No displacement reaction will occur between NaCl solution and copper metal, as copper metal is Less reactive than sodium metal.
(b) Al is less reactive than Mg. So, no displacement reaction will take place.
(c) Ag is less reactive than Fe. So, no displacement reaction will take place.
(d) Cu (copper metal) is more reactive than silver (Ag), so the displacement reaction will take place between AgNO3 solution and copper metal.