Some standard electrode potentials at 298 K are given below:
Pb$$^{2+}$$/Pb -0.13 V
Ni$$^{2+}$$/Ni -0.24 V
Cd$$^{2+}$$/Cd -0.40 V
Fe$$^{2+}$$/Fe -0.44 V
To a solution containing 0.001 M of X$$^{2+}$$ and 0.1 M of Y$$^{2+}$$, the metal rods X and Y are inserted (at 298 K) and connected by a conducting wire. This resulted in dissolution of X. The correct combination(s) of X and Y, respectively, is(are)
(Given: Gas constant, R = 8.314 J K$$^{-1}$$ mol$$^{-1}$$, Faraday constant, F = 96500 C mol$$^{-1}$$)