A. B. C. D.
A.AgI(s)〡I-〡Cl-〡AgCl(s) B.AgI(s)〡I-〡〡Cl-〡AgCl(s) C.Ag(s),AgCl(s)〡Cl-〡〡I-〡AgI(s),Ag(s) D.Ag(s),AgI(s)〡I-〡〡Cl-〡AgCl(s),Ag(s)
A.E2=-2E1 B.E2=2E1 C.E2=-E1 D.E2=E1