Group-13 elements react with $$\mathrm{O}_{2}$$ in amorphous form to form oxides of type $$\mathrm{M}_{2} \mathrm{O}_{3}~(\mathrm{M}=$$ element). Which among the following is the most basic oxide?

During the reaction of permanganate with thiosulphate, the change in oxidation of manganese occurs by value of 3. Identify which of the below medium will favour the reaction.

In the following reaction, 'B' is

The IUPAC name of $$\mathrm{K}_{3}\left[\mathrm{Co}\left(\mathrm{C}_{2} \mathrm{O}_{4}\right)_{3}\right]$$ is:-