Two isomers (A) and (B) with molar mass 184 g/mol and elemental composition C, 52.2%; H. 4.9% and Br 42.9% gave benzoic acid and p-bromobenzoic acid respectively on oxidation with KMnO₄. Isomer 'A' is optically active and gives a pale yellow precipitate when warmed with alcoholic AgNO₃. Isomer 'A' and 'B' are respectively