Question -
Answer -
(a) NaCl solution and copper metal
(b) MgCl2 solution and aluminium metal
(c) FeSO4 solution and silver metal
(d) AgNO3 solution and copper metal
Answer
Option d i.e AgNO3 solution and copper is correct answer. Copper displace the silver cations (reducing them to the elemental metal), in the process copper itself being oxidised to Copper II cations (Cu2+) and going into solution. So silver metal precipitating out and a copper II nitrate solution will be remaining.
Cu(s) + 2AgNO3 (aq) → Cu(NO3)2 (aq)+ 2Ag (s)