The suitable reagent to convert `CH_(3)-CH=CH-CHO` into `CH_(3)-CH_(2)-CH_(2)-CH_(2)-OH`

Options

A. `NaBH_(4)`
B. `LiAlH_(4)`
C. `Zn-Hg//HCl`
D. `H_(2)//Pd`

Explanation

To convert `CH₃-CH=CH-CHO` (an allylic aldehyde) into `CH₃-CH₂-CH₂-CH₂-OH` (a primary alcohol), we need to find a suitable reagent that can reduce both the double bond and the aldehyde group.

### Step-by-Step Solution:

1. **Identify the Functional Groups**:
- The starting compound `CH₃-CH=CH-CHO` contains an alkene (double bond between the second and third carbon) and an aldehyde group (CHO).
- The target compound `CH₃-CH₂-CH₂-CH₂-OH` is a primary alcohol.

2. **Determine the Required Reaction**:
- We need to reduce both the double bond (alkene) and the aldehyde group to achieve the target alcohol. This requires a reagent that can perform both reductions.

3. **Evaluate Possible Reagents**:
- **NaBH₄ (Sodium Borohydride)**: This is a mild reducing agent that can reduce aldehydes to alcohols but does not affect alkenes. Therefore, it is not suitable.
- **LiAlH₄ (Lithium Aluminium Hydride)**: This is a strong reducing agent that can reduce aldehydes to alcohols. However, it does not reduce alkenes. Thus, it is not suitable either.
- **Zn/Hg in HCl (Clemmensen Reduction)**: This reagent reduces aldehydes to alkanes but does not form alcohols. Hence, it is not suitable for our purpose.
- **H₂ in the presence of Palladium (Pd)**: This is a catalytic reduction method that can reduce both alkenes to alkanes and aldehydes to alcohols. Therefore, this reagent is suitable for our conversion.

4. **Conclusion**:
- The suitable reagent to convert `CH₃-CH=CH-CHO` into `CH₃-CH₂-CH₂-CH₂-OH` is **H₂ in the presence of Palladium (Pd)**.

### Final Answer:
**H₂ in the presence of Palladium (Pd)**

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