`underset((A))(PhCOOH)underset(underset((ii)Ag_(2)O //Pt//MeOH)((ii)CH_(2)N_(2)))overset((i)SOCI_(2))rarr (B)`
Product `(B)` is :

Options

A. `PhCONH_2`
B. `PhCH_2 COOH`
C. `PhCH_2 COOMe`
D. `PhCONHMe`

Explanation

To solve the problem step by step, we will analyze the reactions involving benzoic acid (PhCOOH) and the reagents mentioned.

### Step 1: Reaction of Benzoic Acid with SOCl2
- **Starting Material**: Benzoic acid (PhCOOH)
- **Reagent**: Thionyl chloride (SOCl2)
- **Reaction**: When benzoic acid reacts with SOCl2, it converts the carboxylic acid (-COOH) group into an acyl chloride (RCOCl).

**Product**: PhC(=O)Cl (Benzoyl chloride)

### Step 2: Reaction of Benzoyl Chloride with CH2N2
- **Starting Material**: Benzoyl chloride (PhC(=O)Cl)
- **Reagent**: Diazomethane (CH2N2)
- **Reaction**: Diazomethane reacts with benzoyl chloride to form a methyl ester. The reaction involves the nucleophilic attack of the diazomethane on the carbonyl carbon of the acyl chloride, leading to the formation of a methyl ester.

**Product**: PhC(=O)OCH3 (Methyl benzoate)

### Step 3: Reaction of Methyl Benzoate with Ag2O, Pt, and MeOH
- **Starting Material**: Methyl benzoate (PhC(=O)OCH3)
- **Reagents**: Silver oxide (Ag2O), Platinum (Pt), and Methanol (MeOH)
- **Reaction**: In the presence of Ag2O and Pt, the methyl ester undergoes a rearrangement and reduction process. The silver oxide acts as an oxidizing agent, and the platinum serves as a catalyst. This leads to the formation of a more stable product through rearrangement.

**Product**: The final product after rearrangement and reduction is likely to be a substituted compound, specifically an ester.

### Final Product (B)
After going through these steps, the final product (B) can be identified as:
- **Product (B)**: CH2COOMe (Methyl ester of a carboxylic acid)

### Summary
The final product (B) is methyl ester of a carboxylic acid, which can be represented as CH2COOMe.

---