A,B OR A,B,C
(A) SnCl2.2H2O is a reducing agent since Sn2+ tends to convert into Sn4+
(C) First group cations (Pb2+) form insoluble chloride with HCl that is PbCl2 however it is slightly soluble in water and therefore lead +2 ion is never completely precipitated on adding hydrochloric acid in test sample of Pb2+, rest of the Pb2+ ions are quantitatively precipitated with H2S in acidic medium.
So that we can say that filtrate of first group contain solution of PbCl2 in HCl which contains Pb2+ and Cl–
However in the presence of conc. HCl or excess HCl it can produce H2[PbCl4]
So, we can conclude A, B or A,B,C should be answers.
It is not a redox reaction.