An aromatic compound has molecular formula $\mathrm{C}_{7} \mathrm{H}_{7} \mathrm{Br}$. Give the possible isomers and the appropriate method to distinguish them.

• A

  3 isomers; by heating with $\mathrm{AgNO}_{3}$ solution
• B

  4 isomers; by treating with $\mathrm{AgNO}_{3}$ solution
• Correct answer
  C

  4 isomers; by oxidation
• D

  5 isomers; by oxidation

Hence, the correct answer is option: 'C'.