Which one of the following group-15 hydride is the strongest reducing agent?

The set having ions which are coloured and paramagnetic both is :

Thiamine and pyridoxine are also known respectively as :

An organic compound A (C₆H₆O) gives dark green colouration with ferric chloride. On treatment with CHCl₃ and KOH, followed by acidification gives compound B. Compound B can also be obtained from compound C on reaction with pyridinium chlorochromate (PCC). Identify A, B and C.