In view of the signs of $\Delta_{r} G^{\circ}$ for the following reactions:
$PbO_2 + Pb \longrightarrow 2 PbO, \Delta_{r} G^{\circ} < 0$
$SnO_2 + Sn \longrightarrow 2 SnO, \Delta_{r} G^{\circ} > 0$
Which oxidation states are more characteristic for lead and tin?

• A
  For lead $+2,$ for tin $+4$
• B
  For lead $+2,$ for tin $+2$
• C
  For lead $+4,$ for tin $+4$
• D
  For lead $+4,$ for tin $+2$