An organic compound `(A)` on treatment with acetic acid in the presence of sulphuric acid produces an ester `(B)`. `(A)` on mild oxidation gives `( C), ( C)` with `50 %` potassium hydroxide followed by acidification with dilute hydroxide acid generates `(A)` and `(D) ,(D)` with phosphorus pentachloride followed by reaction with ammonia gives `(E) , (E)` on dehydration produces hydrocyanic acid. Identify the compounds `(A), (B), (C), (D)`, and `(E)`.

Explanation