An organic compound `(A)` composed of `C, H,` and `O` gives a characteristic colour with ceric ammonium nitrate. Treatement of `(A)` with `PCl_5` gives `(B)` which reacts with `KCN` to form `( C)`. The reductionof `( C)` with warm `Na//C_2 H_5 OH` produces `(D)` which on heating gives `(E)` with the evolution of ammonia. Pyridine is obtained on treatment of `(E)` with nitrobenzene.

Explanation

To solve the given problem step by step, we need to identify the compounds (A), (B), (C), (D), and (E) based on the reactions described.

### Step 1: Identify Compound (A)
The organic compound (A) is composed of carbon, hydrogen, and oxygen and gives a characteristic color with ceric ammonium nitrate. This suggests that (A) is likely an alcohol or a phenolic compound, as these typically react with ceric ammonium nitrate to give a color change.

**Assumption:** Let's assume (A) is a primary alcohol, specifically ethanol (C2H5OH).

### Step 2: Reaction of (A) with PCl5 to form (B)
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