Which one is phenol ?

Options

A.
B.
C.
D.

Answer

To determine which compound is phenol among the given options, we need to understand the definition of phenol and the concept of functional group priority.

### Step-by-Step Solution:

1. **Understanding Phenol**:
- Phenol is an aromatic compound where a hydroxyl group (-OH) is directly attached to a benzene ring. It is important to identify if the -OH group is the highest priority functional group in the compound.

2. **Analyzing the Options**:
- Let's consider the four options provided (though they are not explicitly listed here). We will analyze each option based on the presence of the -OH group and its priority relative to other functional groups.

3. **Option A**:
- If this option contains both -NO2 (nitro group) and -OH, the -OH group has higher priority than the -NO2 group. Therefore, if -OH is directly attached to the benzene, this option can be considered phenol.

4. **Option B**:
- If this option has -OH and another group like an aldehyde (-CHO), the -CHO group has higher priority than -OH. Hence, this option would not be classified as phenol.

5. **Option C**:
- If this option contains an alcohol that is attached to a benzylic carbon (a carbon adjacent to the benzene ring), it is classified as an aromatic alcohol but not phenol, as the -OH is not directly attached to the benzene ring.

6. **Option D**:
- If this option has -OH attached to a carbon that is also attached to a nitrile (-CN), the -CN group has higher priority than -OH, thus it cannot be considered phenol.

7. **Conclusion**:
- Based on the analysis, the only option where -OH is directly attached to the benzene ring and has higher priority than any other functional group is Option A. Therefore, **Option A is phenol**.

### Final Answer:
**Option A is phenol.**