Which one is not observed when carbon disulphide is added to a mixture of iron fillings and sulphur powder taken in a test tube ?
(a) Sulphur powder dissolves and a yellow solution is formed
(b) Iron fillings remain unaffected
(c) Iron sulphide is formed by the combination of iron of the mixture and of CS2
(d) Solid sulphur reappears when yellow solution is heated
