Final answer:
Tin (II) is stable in oxidation reactions without oxygen and without complex formation, unlike Germanium (II), which is more prone to oxidation. Therefore, Tin (II) is the correct answer.
Step-by-step explanation:
The question revolves around the stability of intermediate oxidation states of certain elements, specifically germanium (II) and tin (II). In an oxygen-free environment, without the formation of complexes, germanium (II) and tin (II) can be considered. Germanium (II) tends to be quite reactive and can oxidize further easily, while tin (II) is more stable and less prone to further oxidation under these conditions.
For instance, in the case of germanium (II), it can be oxidized to germanium (IV), its more stable state, and thus germanium (II) is not very stable on its own. On the other hand, tin (II) often exists in a stable form called stannous compounds and is much less likely to be oxidized without the presence of oxygen.
Conclusion
Based on this, the answer to the question is: (b) Tin (II) is stable with respect to possible oxidation reactions in media without oxygen and without complex formation.