An alkance (A) `C_(5)H_(12)` on chlorination at `300^(@)C` gives a mixtrue of four different monochlorinated derivatives `(B), (C ), (D)`, and `(E )`. Two of these derivatives give the same stable alkene `(F)` on dehydrohalogenation. On oxidation with hot alkaline `KMnO_(4)` followed by acidification, `(F)` gives two products `(G) and (H)`. Give the structrues of `(A) t o (H)` with proper reasoning.