An organic compound A, C₈H₆ on treatment with dilute sulphuric acid-containing mercuric sulphate gives a compound `B`, which can also be obtained from a reaction of benzene with an acid chloride in the presence of anhydrous aluminium chloride. The compound B, when treated with Iodine in aqueous KOH, yields C and a yellow compound D. Identify A B C and D with justification.

Explanation

B is obtained by Fridel crafts,acylation of benzene. Hence B can be
FIGURE
Also B-when treated with I and aqueous KOH gives yellow compound
`therefore D` is `CHI_2`
It also steggests that is a methylketone.