Compound A, (C₈H₉Br) gives a white precipitate when warmed with alcoholic AgnO₃ oxidation of A gives an acid B, (C₈H₆O₄) B easily forms anyhydride on heating. Identify the compound A.

The correct answer is option 4.

Compound A gives a precipitate with alcoholic AgNO₃ (here white is misprinting because the colour of ppt. is light yellow), so it must contain Br in side chain.

On oxidation, it gives C₈H₆O₄, which shows the presence of two alkyl chains attached directly with the benzene nucleus.

Since compound B gives anhydride on heating, the two alkyl substituent must occupy adjacent (1,2) position. Thus, A must be

And the reactions are as follows: