The compound `C_8H_9Cl(A)` on treatments with KCN followed by hydrolysis gives `C_9H_10O_2(B)`.Ammonium salt of B on dry distillation yields C.Which reacts with alkaline solution of bromine to gives `C_8H_11N`.(D),Another compound E `(C_6H_10O)` is obtained by the action of nitrous acid on D. or by the action of aquouspotash on A,E on oxidation gives `F(C_8H_10O)` Which gives the inner anhydride G on heating.
The compound D is reaction with `CHCl_3+NaOH` gives a compound H.The structure of H.

Options

A.
B.
C.
D.

Explanation

To solve the problem step-by-step, we will analyze the transformations of the compounds mentioned in the question.

### Step 1: Identify Compound A
The compound A is given as `C_8H_9Cl`. This suggests that it is likely an aromatic compound with a chlorine substituent. A possible structure could be chlorobenzene with a side chain, such as `C6H5-CH2Cl` (benzyl chloride).

### Step 2: Reaction of A with KCN
When compound A is treated with KCN, a nucleophilic substitution occurs where the chlorine atom is replaced by a cyanide group. This results in the formation of a compound with the formula `C_8H_9CN`.

### Step 3: Hydrolysis of the Cyanide
Upon hydrolysis of the cyanide (`C_8H_9CN`), it converts to a carboxylic acid. The resulting compound B will have the formula `C_9H_{10}O_2`, which can be represented as `C6H5-CH2-COOH` (benzoic acid derivative).

### Step 4: Ammonium Salt of B
The ammonium salt of B can be formed by reacting B with ammonia. This results in the formation of an amide, which we will denote as compound C.

### Step 5: Dry Distillation of Ammonium Salt
When the ammonium salt of B is subjected to dry distillation, it yields compound C. The structure of C is likely a simple amide derived from B.

### Step 6: Reaction of C with Alkaline Bromine
Compound C reacts with an alkaline solution of bromine (Hofmann degradation), resulting in the formation of an amine, which we denote as D. The formula for D is `C_8H_{11}N`.

### Step 7: Reaction of D with Nitrous Acid
When compound D reacts with nitrous acid (HNO2), it undergoes a reaction that replaces the amine group with a hydroxyl group, yielding compound E (`C_6H_{10}O`).

### Step 8: Oxidation of E
Compound E is then oxidized to form compound F, which has the formula `C_8H_{10}O`. This compound can be represented as a dicarboxylic acid.

### Step 9: Heating F to Form Anhydride G
Upon heating compound F, it forms an inner anhydride G. This is a cyclic structure formed from the carboxylic acid groups.

### Step 10: Reaction of D with CHCl3 and NaOH
Finally, compound D reacts with CHCl3 and NaOH, which is known as the carbylamine reaction. This reaction converts the primary amine into an isocyanide (compound H).

### Summary of Compounds
- **A**: `C_8H_9Cl` (Benzyl chloride)
- **B**: `C_9H_{10}O_2` (Carboxylic acid)
- **C**: Amide derived from B
- **D**: `C_8H_{11}N` (Amine)
- **E**: `C_6H_{10}O` (Alcohol)
- **F**: `C_8H_{10}O` (Dicarboxylic acid)
- **G**: Inner anhydride formed from F
- **H**: Isocyanide formed from D