Which of the following statements is `//` are correct ?

Options

A. The reductive and ocidative oxonolyses or `m-` and `p-` xylens give the same product.
B. The reductive ozonolysis of `o-`xylene `(1,2-`dimethyl benzene `)` gives glyoxal `+` methyglyoxal in `3:2:1` ratio.
C. The ozonolysis of `o-`xylene establishes the Kekule's structure of benzene and also proves the existence of resonance in benzene.
D. The oxidation of benzene with acidic `KMnO_(4)` gives `3 mol` oxalic acid.

Explanation

To determine which statements regarding ozonolysis and oxidation reactions are correct, we will analyze each statement step by step.

### Step 1: Analyze Statement 1
**Statement 1:** The reductive and oxidative ozonolysis of meta and para xylene gives the same product.

- **Explanation:**
- Meta xylene has two methyl groups at the 1,3-positions on the benzene ring, while para xylene has them at the 1,4-positions.
- During ozonolysis, the double bonds in the alkene are cleaved, and the products formed from both meta and para xylene will be the same due to the symmetrical nature of the products formed from these positions.
- The products are typically glyoxal (CHOCHO) and methylglyoxal (CH3C(=O)CHO).

- **Conclusion:** Statement 1 is **correct**.

### Step 2: Analyze Statement 2
**Statement 2:** The reductive ozonolysis of ortho xylene gives glyoxal, methylglyoxal, and dimethylglyoxal in a 3:2:1 ratio.

- **Explanation:**
- Ortho xylene has two methyl groups at the 1,2-positions on the benzene ring.
- Upon ozonolysis, the breaking of the bonds leads to the formation of glyoxal, methylglyoxal, and dimethylglyoxal.
- The products obtained from ortho xylene are indeed in the ratio of 3:2:1 (glyoxal:methylglyoxal:dimethylglyoxal).

- **Conclusion:** Statement 2 is **correct**.

### Step 3: Analyze Statement 3
**Statement 3:** The ozonolysis of ortho xylene establishes the Kekulé structure of benzene and also proves the existence of resonance in benzene.

- **Explanation:**
- The ozonolysis of ortho xylene does provide evidence for the structure of benzene and its resonance forms.
- The products formed during ozonolysis can be used to illustrate the resonance stabilization of benzene, supporting the idea of multiple contributing structures (Kekulé structures).

- **Conclusion:** Statement 3 is **correct**.

### Step 4: Analyze Statement 4
**Statement 4:** The oxidation of benzene in acidic KMnO4 gives 3 moles of oxalic acid.

- **Explanation:**
- Benzene is a very stable molecule due to its delocalized π-electrons and resonance.
- It does not undergo oxidation to form oxalic acid when treated with acidic KMnO4. Instead, benzene is resistant to such strong oxidizing conditions.

- **Conclusion:** Statement 4 is **incorrect**.

### Final Summary
- **Correct Statements:** 1, 2, and 3 are correct.
- **Incorrect Statement:** 4 is incorrect.