$A$ sulphate of a metal $(A)$ on heating evolves two gases $(B)$ and $(C)$ and an oxide $(D).$ Gas $(B)$ turns $K_2Cr_2O_7$ paper green while gas $(C)$ forms a trimer in which there is no $S-S$ bond. Compound $(D)$ with $HCl$ reacts to form a compound $(E)$ which exists as a dimer. Compounds $(A)$,$(B)$,$(C)$,$(D)$ and $(E)$ are respectively:

• A
  $FeSO_4, SO_2, SO_3, Fe_2O_3, FeCl_3$
• B
  $Al_2(SO_4)_3, SO_2, SO_3, Al_2O_3, FeCl_3$
• C
  $FeS, SO_2, SO_3, FeSO_4, FeCl_3$
• D
  $FeS, SO_2, SO_3, Fe_2(PO_4)_3, FeCl_2$