An organic compound (A) `(C_(6)H_(6)O)` gives maximum of two isomers (B) and ( C), When an alkaline solution of (A) is refluxed with chloroform. (B) on oxidation gives acid (D). The acid (D) is also obtained by treating. Sodium salt of (A) with `CO_(2)` under pressure followed by hydrolysis, Identify the compounds (A), (B), (C) and (D) and explains with proper chemical reactions.

Explanation

(i) When alkaline solution of (A) is refluxed with chloroform, isomers (B) and (C ) are obtained.
(ii) (B) on oxidation gives acid (D).

(iii) The acid (D) is also obtained by treating, sodium salt of (A) witih `CO_(2)` under pressure followed by hydrolysis.