Consider the following reaction,
`{:(CHO" "COO^(-)),("| "+OH^(-) rarr "|"),(CHO" "CH_(2)OH):}`
Select the incorrect statement.

Options

A. It is not a disproportionation reaction.
B. It is intramolecular redox reaction.
C. `OH^(-)` is a reducing as well as oxidising agent.
D. `{:(CHO),("|"),(CHO):}` is a reducing as well as oxidising agent.

Explanation

To solve the question regarding the given reaction and select the incorrect statement, let's analyze the reaction step by step.

### Step 1: Identify the Reactants and Products
The reaction provided is:
\[ \text{CHO} \, \text{COO}^- + \text{OH}^- \rightarrow \text{CHO} \, \text{CH}_2\text{OH} \]

Here, we have:
- **CHO** (an aldehyde)
- **COO^-** (the carboxylate ion)
- **OH^-** (hydroxide ion)
- **CH2OH** (an alcohol)

### Step 2: Determine Oxidation and Reduction
In this reaction:
- The aldehyde group (CHO) is being oxidized to the carboxylate ion (COO^-).
- The hydroxide ion (OH^-) is involved in the reduction of another aldehyde group (CHO) to form the alcohol (CH2OH).

### Step 3: Classify the Reaction
Since one part of the molecule is being oxidized while another part is being reduced, this indicates that:
- This is an **intramolecular redox reaction** because both oxidation and reduction occur within the same molecule.
- It is also a **disproportionation reaction** because the same species (the aldehyde) is undergoing both oxidation and reduction.

### Step 4: Analyze the Statements
Now, let's evaluate the statements provided in the question:

1. **Statement 1**: It is not a disproportionation reaction.
- **Incorrect**: This is a disproportionation reaction since one species is undergoing both oxidation and reduction.

2. **Statement 2**: It is an intramolecular redox reaction.
- **Correct**: This is indeed an intramolecular redox reaction.

3. **Statement 3**: OH is a reducing as well as an oxidizing agent.
- **Correct**: The hydroxide ion can act as both a reducing agent (in the reduction of CHO to CH2OH) and an oxidizing agent (in the oxidation of another CHO).

4. **Statement 4**: This molecule is a reducing as well as an oxidizing agent.
- **Correct**: The molecule involved is acting as both a reducing agent (by reducing another species) and an oxidizing agent (by being oxidized itself).

### Conclusion
Based on the analysis:
- The **incorrect statement** is **Statement 1**: It is not a disproportionation reaction.