Identify (X), (Y) and (Z) in the given reaction.
`X +Y overset(Z) to underset("3-Hydroxybutanal")(CH_(3)-overset(OH)overset(|)(CH)-CH_(2))-CHO`

Options

A. `{:(X,Y,Z),(HCHO,CH_(3)CHO,KOH):}`
B. `{:(X,Y,Z),(CH_(3)CHO,CH_(3)CHO,NaOH):}`
C. `{:(X,Y,Z),(CH_(3)CH_(2)OH,HCHO,H_(2)SO_(4)):}`
D. `{:(X,Y,Z),(CH_(3)CH_(2)CHO,HCHO,"Dry ether"):}`

Answer

To identify (X), (Y), and (Z) in the given reaction that produces 3-hydroxybutanal (CH₃-CH(OH)-CH₂-CHO), we can follow these steps:

### Step 1: Understand the Product Structure
The product is 3-hydroxybutanal, which indicates that it is an aldehyde with a hydroxyl group (-OH) on the third carbon. This suggests that the reaction involves the formation of a β-hydroxy aldehyde.

### Step 2: Identify the Type of Reaction
The formation of β-hydroxy aldehydes typically occurs through an aldol condensation reaction. In this reaction, two carbonyl compounds (aldehydes or ketones) react in the presence of a base to form a β-hydroxy carbonyl compound.

### Step 3: Determine the Reactants (X and Y)
Since we are looking for two carbonyl compounds that can react to form 3-hydroxybutanal, we can consider the simplest aldehydes. The most likely candidates are:
- X: Acetaldehyde (CH₃CHO)
- Y: Acetaldehyde (CH₃CHO)

Both of these compounds have the necessary functional groups and alpha hydrogens required for the aldol reaction.

### Step 4: Identify the Reagent (Z)
The reagent (Z) in an aldol condensation reaction is typically a strong base. Common bases used in such reactions include sodium hydroxide (NaOH) or potassium hydroxide (KOH).

### Conclusion
Based on the analysis:
- (X) = Acetaldehyde (CH₃CHO)
- (Y) = Acetaldehyde (CH₃CHO)
- (Z) = Sodium hydroxide (NaOH) or Potassium hydroxide (KOH)

Thus, the complete reaction can be summarized as:
\[ \text{Acetaldehyde (X)} + \text{Acetaldehyde (Y)} \overset{\text{NaOH (Z)}}{\rightarrow} \text{3-Hydroxybutanal} \]