Compound $\left( A \right),\,{C_8}{H_9}Br,\,\,\,$ gives a white precipitate when warmed with alcoholic $AgN{O_3}.$ Oxidation of $(A)$ gives an acid $\left( B \right),$ ${C_8}{H_6}{O_4}.\,\,\left( B \right)$ easily forms anhydride on heating. Identify the compound $(A).$