It is because of inability of ns 2 electrons of the valenc...

Sn 4+ is reducing while Pb 4+ is oxidising

Sn 2+ is reducing while Pb 4+ is oxidising

Sn 2+ is oxidising while Pb 4+ is reducing

Sn 2+ and Pb 2+ are both oxidising and reducing

It is because of inability of ns² electrons of the valence shell to participate in bonding that

Sn⁴⁺ is reducing while Pb⁴⁺ is oxidising

Sn²⁺ is reducing while Pb⁴⁺ is oxidising

Sn²⁺ is oxidising while Pb⁴⁺ is reducing

Sn²⁺ and Pb²⁺ are both oxidising and reducing

Not Attempted