Which of the following carboxylic acids undergoes decarboxylation easily ? Explain briefly.
(i) `C_(6) H_(5) -CO-CH_(2)-COOH`
(ii) `C_(6) H_(5) -CO-COOH`

iii. `C_(6)H_(5)-underset(OH)underset(|)(CH)-COOH` (iv) `C_(6) H_(5) - underset(underset(NH_2) (|))(CH) -COOH`.

Explanation

To determine which carboxylic acid undergoes decarboxylation easily, we need to analyze the structures of the given compounds.

### Step 1: Identify the Structures
The compounds are:
1. \( C_6H_5-CO-CH_2-COOH \) (Beta-keto carboxylic acid)
2. \( C_6H_5-CO-COOH \) (Alpha-keto carboxylic acid)
3. \( C_6H_5-CH(OH)-COOH \) (Hydroxy carboxylic acid)
4. \( C_6H_5-CH(NH_2)-COOH \) (Amino carboxylic acid)
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