An organic compound A having molecular formula C6H6O gives a violet colour with neutral FeCl3 ​ solution. A on treatment with CO2​ and NaOH at 400 K under pressure gives B which on acidification gives a compound C. The compound C reacts with acetyl chloride to give D which is popular pain killer. Deduce the structure of A, B, C and D.

What is the use of compound D?

in perfumery as a flavouring agent as an antipyretic as an analgesic as an intestinal antiseptic.

as an analgesic