Acidified sodium fusion extract on addition of ferric chloride solution gives blood red colouration. This confirms the presence of which of the following elements?

Acidified sodium fusion extract on addition of ferric chloride solution gives blood red colouration, which confirms the presence of N and S both.Na+C+N+S⟶NaSCNFe3++SCN-⟶[Fe(SCN)]2+                                Blood red