Assertion : In the presence of alkaline `KMnO_(4)` 4-methylacetophenone is oxidised to benzoic acid.
Reason : Keto group is oxidised to `-COOH` group.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Explanation

To solve the question, we need to analyze both the assertion and the reason provided.

### Step 1: Understand the Compound
The compound in question is 4-methylacetophenone. Its structure can be represented as follows:
- It has a benzene ring with an acetophenone (C6H5C(O)CH3) group and a methyl group (CH3) at the para position (4-position) of the benzene ring.

### Step 2: Reaction with Alkaline KMnO4
When 4-methylacetophenone is treated with alkaline KMnO4, a strong oxidizing agent, it undergoes oxidation. The oxidation process involves:
- The keto group (C=O) in the acetophenone part is oxidized to a carboxylic acid (-COOH).
- Additionally, the methyl group (CH3) is also oxidized to a carboxylic acid (-COOH).

### Step 3: Products of the Reaction
The oxidation of both the keto group and the methyl group leads to the formation of terephthalic acid (C6H4(COOH)2), which has two carboxylic acid groups. This is different from benzoic acid (C6H5COOH), which only has one carboxylic acid group.

### Step 4: Evaluate the Assertion and Reason
- **Assertion**: "In the presence of alkaline KMnO4, 4-methylacetophenone is oxidized to benzoic acid." This statement is **false** because the product is not benzoic acid; it is terephthalic acid.
- **Reason**: "Keto group is oxidized to -COOH group." This statement is also **false** because it implies that only the keto group is oxidized, while in reality, both the keto group and the methyl group are oxidized to carboxylic acids.

### Conclusion
Both the assertion and the reason are incorrect. Therefore, the correct answer is that both the assertion and the reason are false.

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