Consider the following standard electrode potentials (E^o in volts) in aqueous solution :

Element	M3+ /M	M+ /M
A1	-1.66	+ 0.55
T1	+1.26	- 0.34

Based on these data, which of the following statements is correct ?

A metal ‘M’ reacts with nitrogen gas to afford ‘M₃N’. ‘M₃N’ on heating at high temperature gives back ‘M’ and on reaction with water produces a gas ‘B’. Gas ‘B’ reacts with aqueous solution of CuSO₄ to form a deep blue compound. ‘M’ and ‘B’ respectively are :

The number of S = O and S − OH bonds present in peroxodisulphuric acid and pyrosulphuric acid respectively are :

A mixture containing the following four compounds is extracted with $$1M$$ $$HCl.$$ The compound that goes to aqueous layer is :