`H_(2)C=CH-CH_(2)-overset(O)overset(||)C-H overset("Reagent")rarr CH_(2)-CH_(2)-CH_(2)-CH_(2)-OH`
Appropriate reagent for above conversion will be

Options

A. Metal `+ H_(2)`
B. `LiAlH_(4)`
C. `NaBH_(4)`
D. All

Explanation

To solve the problem, we need to identify the appropriate reagent that can convert the given alkene (H₂C=CH-CH₂-CHO) to the desired product (CH₂-CH₂-CH₂-CH₂-OH).

### Step-by-Step Solution:

1. **Identify the Reactants and Products:**
- The starting material is an alkene (H₂C=CH-CH₂-CHO) which contains a double bond and an aldehyde functional group.
- The target product is a straight-chain alcohol (CH₂-CH₂-CH₂-CH₂-OH).

2. **Understand the Reaction Type:**
- The conversion involves the reduction of the alkene and the aldehyde to form an alcohol.
- The double bond in the alkene needs to be converted to a single bond, and the aldehyde needs to be reduced to an alcohol.

3. **Select the Appropriate Reagent:**
- To achieve this transformation, we need a reagent that can reduce both the alkene and the aldehyde.
- A common reagent that can perform such reductions is Lithium Aluminum Hydride (LiAlH₄) or Sodium Borohydride (NaBH₄). However, since we need to reduce the alkene as well, a more powerful reagent like Hydrogen (H₂) in the presence of a catalyst (such as palladium or platinum) can be used.

4. **Write the Reaction:**
- The reaction can be represented as:
\[ H₂C=CH-CH₂-CHO + H₂ \xrightarrow{Pd/Pt} CH₂-CH₂-CH₂-CH₂-OH \]

5. **Conclusion:**
- The appropriate reagent for the conversion of the given alkene to the desired alcohol is Hydrogen gas (H₂) in the presence of a catalyst like palladium (Pd) or platinum (Pt).

### Final Answer:
The appropriate reagent for the conversion is Hydrogen gas (H₂) with a catalyst (Pd or Pt).

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