An aromatic compound 'A' ( molecular formula C8H8 0 ) gives positive 2,4,DNP test. It gives a yellow precipitate of compound 'B' on treatment with iodine and sodium hydroxide solution. Compound 'A' does not give Tollen's or Fehling's test. On drastic oxidation with potassium permanganate it forms a carboxylic acid C (molecular formulaC7H6 02 , which is also formed along with yellow compound in the above reaction. Identify A, B and C and write all the reaction involved. ​