Which amine yields N-nitroso amine after treatment with nitrous acid `(NaNO_(2),HCl)` ?

Options

A.
B.
C.
D.

Explanation

To determine which amine yields N-nitroso amine upon treatment with nitrous acid (NaNO₂ in HCl), we need to analyze the behavior of different types of amines when they react with nitrous acid.

### Step-by-Step Solution:

1. **Identify Types of Amines**:
- Amines can be classified into three categories: primary, secondary, and tertiary.
- **Primary amine**: Contains two hydrogen atoms attached to nitrogen (R-NH₂).
- **Secondary amine**: Contains one hydrogen atom and two organic groups attached to nitrogen (R-NH-R').
- **Tertiary amine**: Contains no hydrogen atoms attached to nitrogen (R-NR'R'').

2. **Reactions with Nitrous Acid**:
- **Primary amines** react with nitrous acid to form diazonium salts (R-N₂⁺Cl⁻).
- **Secondary amines** react with nitrous acid to form N-nitrosamines (R-N(NO)R').
- **Tertiary amines** do not form N-nitrosamines; instead, they undergo electrophilic substitution reactions.

3. **Conclusion Based on Reaction Types**:
- Since we are looking for an amine that yields N-nitroso amine, we focus on secondary amines.
- Secondary amines are the only type that directly forms N-nitrosamines when treated with nitrous acid.

4. **Example of Secondary Amine**:
- For instance, if we take a secondary amine like dimethylamine (NH(CH₃)₂), upon treatment with nitrous acid, it will yield N-nitrosodimethylamine.

5. **Final Answer**:
- Therefore, the amine that yields N-nitroso amine upon treatment with nitrous acid is a **secondary amine**.