Which of these will give aldehyde ?

Options

A. `CH_(3)-CH_(2)-NO_(2) overset((i)" conc. NaOH")underset((ii) H_(2)SO_(4))to`
B. `C_(6)H_(5)-overset(O)overset(||)C-Cl overset(H_(2)//Pd-"BaSO"_(4))to`
C. `CH_(3)-CH_(2)-CN overset((i) SnCl_(2))underset((ii) H_(2)"O"//overset(oplus)H//Delta)to`
D. All of the above

Explanation

To determine which of the given reactions will produce an aldehyde, we will analyze each option step by step.

### Step 1: Analyze the First Reaction
1. **Reaction Overview**: The first reaction involves a compound with a structure that includes a CH3 group, a CH2 group, and a NO2 group.
2. **Mechanism**: The NO2 group undergoes a reaction where it interacts with the hydrogen atom, resulting in the formation of a double bond and a positively charged nitrogen.
3. **Formation of Aldehyde**: Upon further reaction with concentrated NaOH, the acidic hydrogen is removed, leading to the formation of a sodium salt. When treated with H2SO4 (which provides H+ ions), the product formed includes CH3CHO (an aldehyde).
4. **Conclusion**: Aldehyde is produced in this reaction.

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