`Ph-NH_(2) overset(HNO_(2))underset(0^(@)C) to A overset(HF)underset(BF_(3))to B overset(Delta)toC`, C is:

Options

A. p- aminoazoxybenzene
B. m-aminoazobenzene
C. p-aminoazobenzene
D. All of these

Answer

To solve the question step by step, we need to analyze the reactions involved in the transformation of the compound starting from Ph-NH2 (aniline) to the final product C.

### Step-by-Step Solution:

1. **Identify the starting compound**: The starting compound is aniline (Ph-NH2).

2. **First Reaction with HNO2**:
- Aniline reacts with nitrous acid (HNO2) at 0°C. This reaction leads to the formation of a diazonium salt.
- The reaction can be represented as:
\[ \text{Ph-NH}_2 + \text{HNO}_2 \rightarrow \text{Ph-N}_2^+ \text{(Diazonium salt)} + \text{H}_2\text{O} \]
- The product A is the diazonium salt (Ph-N2+).

3. **Second Reaction with HF and BF3**:
- The diazonium salt (A) is then treated with hydrofluoric acid (HF) in the presence of boron trifluoride (BF3). This reaction leads to the formation of fluorobenzene.
- The reaction can be represented as:
\[ \text{Ph-N}_2^+ + \text{HF} \rightarrow \text{Ph-F} + \text{N}_2 + \text{H}^+ \]
- The product B is fluorobenzene (Ph-F).

4. **Third Reaction with Heat (Δ)**:
- The fluorobenzene (B) is then subjected to heat. Under heating, fluorobenzene can undergo various reactions, but in this context, it typically leads to the formation of benzene (C) through elimination of HF.
- The reaction can be represented as:
\[ \text{Ph-F} \xrightarrow{\Delta} \text{C6H6} + \text{HF} \]
- The final product C is benzene (C6H6).

### Final Answer:
C is benzene (C6H6).