`{:(" List-I"," List-II"),((P)"Alcohol",(1)-COOH),((Q)"Aldehyde",(2) -OH),((R )"Ketone",(3)-CHO),((S) "Carboxylic acid",(4) -overset(O)overset(||)C-):}`

Options

A. P-1, Q-2, R-4, S-1
B. P-2, Q-3, R-4, S-1
C. P-3, Q-2, R-1, S-4
D. P-4, Q-2, R-3, S-1

Answer

To solve the problem of matching the functional groups in List-I with their corresponding structures in List-II, we will follow these steps:

### Step-by-Step Solution:

1. **Identify the Functional Groups in List-I:**
- P: Alcohol
- Q: Aldehyde
- R: Ketone
- S: Carboxylic acid

2. **Identify the Structures in List-II:**
- (1) -COOH (Carboxylic acid)
- (2) -OH (Alcohol)
- (3) -CHO (Aldehyde)
- (4) -C(=O)- (Ketone)

3. **Match Each Functional Group with Its Structure:**
- **Alcohol (P)**: The functional group for alcohol is -OH. Therefore, we match:
- P → (2) -OH
- **Aldehyde (Q)**: The functional group for aldehyde is -CHO. Therefore, we match:
- Q → (3) -CHO
- **Ketone (R)**: The functional group for ketone is -C(=O)-, which is represented as a carbonyl group between two carbon atoms. Therefore, we match:
- R → (4) -C(=O)-
- **Carboxylic Acid (S)**: The functional group for carboxylic acid is -COOH. Therefore, we match:
- S → (1) -COOH

4. **Summarize the Matches:**
- P → (2)
- Q → (3)
- R → (4)
- S → (1)

5. **Final Matching:**
- The final matches are:
- P (Alcohol) → (2) -OH
- Q (Aldehyde) → (3) -CHO
- R (Ketone) → (4) -C(=O)-
- S (Carboxylic acid) → (1) -COOH

### Conclusion:
The correct matching is:
- P → 2
- Q → 3
- R → 4
- S → 1

Thus, the answer is **2341**, which corresponds to option B.