Phenol `overset(Aerial)underset(oxid)rarr` coloured. This is due to the formation of:

Options

A.
B.
C.
D. All

Explanation

To solve the question regarding the coloration of phenol upon aerial oxidation, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Aerial Oxidation**:
- Aerial oxidation refers to the oxidation of phenol when it is exposed to air (oxygen). This process can lead to the formation of various oxidized products.

2. **Identifying the Products**:
- When phenol undergoes aerial oxidation, it can form two significant compounds:
- **Phenolquinone**
- **Para-Benzoquinone**
- These compounds are formed due to the oxidation of the hydroxyl group (-OH) present in phenol.

3. **Color Formation**:
- The colored nature of the products is due to the presence of conjugated systems in the molecular structure of the oxidized compounds.
- The formation of **Phenolquinone** and **Para-Benzoquinone** introduces double bonds and resonance structures, which can absorb visible light, leading to the appearance of color.

4. **Color Characteristics**:
- The colors observed can vary from pink to red to brown, depending on the concentration and the specific conditions of the oxidation process.
- These colors arise from the electronic transitions within the conjugated systems of the oxidized compounds.

5. **Conclusion**:
- Therefore, the coloration observed in phenol after aerial oxidation is due to the formation of **Phenolquinone** and **Para-Benzoquinone**, which possess conjugated systems that absorb light in the visible spectrum.

### Final Answer:
Phenol upon aerial oxidation gives colored compounds due to the formation of **Phenolquinone** and **Para-Benzoquinone**.